Official MPG Figures Unrealistic, Says UK Auto Magazine

Taco Cowboy (5327) writes "Research carried out by UK consumer magazine What Car? which concluded that official manufacturers' MPG figures are unrealistic. Based on the research, new car buyers in the UK who trust official, government-sanctioned fuel economy figures will pay an average of £1,000 (€1,216) more than they expect on fuel over a three-year period. Since launching True MPG two years ago, What Car? has tested almost 400 cars in real-world conditions, using cutting-edge test equipment and achieving economy figures that are on average 19% lower than the government figures."

Comments

Real-world conditions

[Anonymous Coward]

Under-inflated tires, lousy fuel, ignored maintenance, rapid acceleration, more than one occupant / actual cargo, stop-and-go traffic, air pollution, air pressure variation, air temperature variation, elevation variation...

And these are just a few of the things that would cause your "official" MPG figures to deviate from observations.

Re:Real-world conditions

[Anonymous Coward]

Probably also driving too fast... European emission standards require testing at 90km/h, while the max speed in most EU countries is 120 or 130km/h

Re:Real-world conditions

[Chrisq]

Under-inflated tires, lousy fuel, ignored maintenance, rapid acceleration, more than one occupant / actual cargo, stop-and-go traffic, air pollution, air pressure variation, air temperature variation, elevation variation...

And these are just a few of the things that would cause your "official" MPG figures to deviate from observations.

That's all true, but manufacturers go to great lengths to inflate the figure. They disconnect the alternator, tape up cracks in the bodywork to improve airflow, remove wing mirrors(!), disconnect the brakes to reduce friction and use special oils in the engine to improve efficiency. Figures are not just a bit off but way off. My car has an official figure of 68.9mpg. On a good trip, driving on a flat road at about 70 mph I can get 54, but my usual average is 35 mpg. This is with gentle driving, I can easily take it down to 25 if I don't take care.

Re:Real-world conditions

[Anonymous Coward]

That's all true, but manufacturers go to great lengths to inflate the figure.

I do wonder how someone so odiously dishonest as to participate in the practices you describe could ever become an engineer for a successful international brand.

Then, as someone who has been self-employed since 2003 and who has seen such a huge change in the way clients behave over the past decade, I wonder whether odious dishonesty today is a job requirement.

Re:Real-world conditions

[Anonymous Coward]

Not so much about being dishonest... It's more like one competitor starting to do it and the rest has to follow or their product looks bad.

Re:Real-world conditions

[Zocalo]

Yeah, lots of things could impact efficiency, car condition and driving style being the main two. I keep my tire pressures up, use decent fuel, check the oil regularly, don't keep a load of junk in the car, don't accellerate too quickly, decellerate by anticipating traffic and lifting off as much as possible, try to time journeys to avoid heavy traffic, and, most importantly, keep the speed down to something more realistic (without being a mobile chicane) than those who drive as fast as they think they can get away with. That all gives me about 40% better mileage than what I'm apparently supposed to, which at my mileage and EU fuel prices adds to a saving well in excess of what I'm supposed to be losing according to TFA, although that does drop significantly if I drive more aggressively. Did they take that kind of stuff into account with their tests, or just get a bunch of random drivers who quite possibly don't have a very efficient driving style to drive a precribed route and then submit fuel usage figures? They don't say, just "experienced engineers, who drive test vehicles over a variety of real roads, including motorways, 'A' and 'B' roads and through towns and villages", which says nothing about the car itself.

Re:Real-world conditions

[Thanshin]

I'm surprised they don't test the mpg by throwing the cars from a high altitude bomber.

Re:Real-world conditions

[Luckyo]

All the tricks you mention would only improve the number by a fairly small percentarge, likely low double digits.

You are claiming that your normal usage doubles your fuel consumption. That suggests that most of the problem is in your driving style.

Re:Real-world conditions

[Anonymous Coward]

Under-inflated tires, lousy fuel, ignored maintenance, rapid acceleration, more than one occupant / actual cargo, stop-and-go traffic, air pollution, air pressure variation, air temperature variation, elevation variation...

And these are just a few of the things that would cause your "official" MPG figures to deviate from observations.

EXACTLY.

And for more evidence of this, I've been driving for almost 30 years now. Every car I've purchased has actually achieved better gas mileage than advertised, likely because of my driving habits.

In summary, people are spoiled and impatient. This leads to keeping the A/C pumping when it's comfortable outside, and general procrastination gives birth to lead-foot disease.

Re:Real-world conditions

[Ginger Unicorn]

Why on earth do government let the manufacturers report their own consumption figures? That's like letting me write my own MOT certificate every year.

Re:Real-world conditions

[Anonymous Coward]

Not so much about being dishonest... It's more like one competitor starting to do it and the rest has to follow or their product looks bad.

In other words, yes, being totally, utterly, corrupted-to-the-bone-marrow, screw-the-customer dishonest!

Re:Real-world conditions

[Pieroxy]

infinite mpg looks suspicious so far. Give it time.

Re:Real-world conditions

[Rosco P. Coltrane]

I'm a hypermiler. I get 51 mpg out of my diesel minivan, But I have to work really hard at it, drive slowly, draft trucks, avoid braking, coast and engine-brake whenever I can. It's so much work I usually can't drive with the radio on, to avoid distraction.

Fuelly shows the same model/year minivan routinely gets 35 mpg or less in normal driving condition. So it's almost entirely a matter of driving style rather than technical tricks.

Re:Real-world conditions

[MightyYar]

This story is about European standards which are a bit wacky, but I know they get spot-checked in the US. Hyundai paid out a huge settlement for (apparently honestly) screwing up the testing.

Remember that your competitors are probably testing your cars, too :)

Re:Real-world conditions

[Anonymous Coward]

Most EU standards you can self-certify for. This is good for most part as it does not harm small companies that cannot afford a test lab to do tests you can easily do yourself just as accurate.

Re:Real-world conditions

[Anonymous Coward]

Capitalism at its finest!

Re:Real-world conditions

[Anonymous Coward]

Yes, I too get higher mileage than the official estimates for my last two cars, by driving carefully.

Re:Real-world conditions

[Lumpy]

Also set up wrong by the manufacturer. The 2007 honda civic has a highway MPG rating of 40mpg. I regularly get 44-46 while speeding after I fixed their design flaw in the rear end. they set the car with significant negative rear camber and with about 2 degrees of toe, I reset it to zero and zero and not only did fuel mileage numbers skyrocket by 10-15% but rear tire wear dropped to zero or undetectable. From what I can tell they STILL sell civics with this flaw, and the Honda Fit as well suffers from it.

Granted I only have about 10,000 miles of testing on this new adjustment, but there is no measurable tire wear on the rear and my wife has been driving it to work and back daily on a 45 mile commute as if she was in an indy car race trying to do 75-80mph. Gas mileage is measured two ways. 1st odometer+fuel used at the pump and a Scan Gauge I installed. they are within 1mpg of each other.

There is only one drawback to the change, the car is slightly more sensitive to steering input. I notice it, she does not. I am going to next add 2 degree of camber from the front to make it closer to zero as well as remove 2 degree of toe that may make the steering a bit too twitchy but you never know until you try. right now it has more than 8 degrees of camber and what looks like 9 degrees of toe. so the removal of that should further boost highway fuel economy but not as significantly as the rear end change. The rear was doing nothing but scrubbing the tires all the time, as most civic owners will tell you they have to replace the rear tires a lot as they start to cup, this is because of the dramatic flaw in how the rear end is set up on all 8th gen Civics.

Oh and I do these alignment changes in my garage, the "laser alignment" crap is nothing more than a scam. You can do a better alignment on your garage floor or driveway than the "experts" with the "highly advanced laser system" can.

Re:Real-world conditions

[rmdingler]

Even if the honest reporting of fuel economies was a high priority, these folks who measure vehicles versus a standardized test would get better and better results over time using the same automobile. Rather than a general improvement in mileage rates for the average customer, the results would be indicative of learning to perform better on the test.

The purchaser of the vehicle would be ensured a mileage rating that was measured in a specific way, which may or may not be reflective of the way he will be driving.

That said, even despite cheating, conniving, fudging numbers, and leaving "light trucks" as a separate category, the CAFE legislation enacted by the US gov't has made a marked improvement in the average fuel economy of new vehicles... whether or not that led to actual conservation or more driving is for another argument.

Re:Real-world conditions

[KozmoStevnNaut]

Also set up wrong by the manufacturer. The 2007 honda civic has a highway MPG rating of 40mpg. I regularly get 44-46 while speeding after I fixed their design flaw in the rear end. they set the car with significant negative rear camber and with about 2 degrees of toe, I reset it to zero and zero and not only did fuel mileage numbers skyrocket by 10-15% but rear tire wear dropped to zero or undetectable. From what I can tell they STILL sell civics with this flaw, and the Honda Fit as well suffers from it.

That's not a flaw, it's a deliberate design to improve stability and handling, especially during mid-corner corrections and emergency maneuvers. The slight toe-in also helps straight line stability.

My car (Peugeot 406) is setup like that as well, it has enough negative rear camber that it is immediately noticeable when looking at the car. If you try to "correct" this by dialing out the camber, the car will be less stable over mid-corner bumps, and the small amount of passive rear steering built in the rear suspension will be negated, further worsening the handling.

What you have done is make your car go from being relatively neutral in corners, to having positive camber when the suspension is loaded up. If you've ever read "Unsafe at any speed" or seen an old VW Beetle corner hard, you will know that having positive camber is one of the most dangerous situations you can be in. So you've actually made your car significantly less safe, all for the sake of a few MPG. Congratulations, I hope you're proud.

Re:Real-world conditions

[Lumpy]

If it eats the rear tires within 15,000 miles and introduces a vibration within 8000 miles due to cupping, It's a flaw.

Re:Real-world conditions

[Anonymous Coward]

i have been hypermiling, too. my car is a 1996 corvette with 110000
miles on it. i get 15.5 mpg with all the tricks, and 14.7 if i drive with
wild abandon. the same car on the highway gets closer to 30 with
no special effort. (epa figures: 15/24.)

say hi to flash for me.

Re:Real-world conditions

[KozmoStevnNaut]

Cupping has nothing to do with camber or toe, it happens because of bad damping and is a completely unrelated issue.

Regarding the rear tire wear, perhaps you should try a different make and model of tire, or you could try driving less aggressively or less over-loaded. 15000 miles is perfectly normal for a tire with sporting pretensions.

Re:Real-world conditions

[Jeff DeMaagd]

There are a lot of factors that affect fuel mileage, but it's been suggested that the ECM can detect whether they're on a standardized emissions or efficiency test and change the settings accordingly. I wish I remembered where I had seen that article.

Re:Real-world conditions

[Anonymous Coward]

It appears as though you don't understand capitalism. In true capitalism there would be no barriers to entry, thus this behavior would have competitors that could easily be start up and would quickly cause businesses that practiced such dishonest means to loose income, thus eventually forcing them to the honest track. This however is not possible with some fields (cars being one). To create a good car you need a lot of resources, that are not available to most of us starting out. This still isn't a serious problem as one can find lenders to forward these funds that would allow them to build these better cars. However, the one thing that can not be avoided in our current system is patents, these grant a monopoly to a singular entity. Because of them we can not create a better system, as pretty much everything you expect in a vehicle is patented. If you do not play by their rules there is no reason they have to let you use their patents. We would have a fully open source cell phone now if it were not for patents, and a line of good open source cars that would rival the cars on the market.
Capitalism is not at fault for this, it the exact opposite. Monopolies of any kind are anti capitalist, and they are the corner stone of what we hate about capitalism. If you dislike something just make something better, well not with the monopolistic patents. They will be used to stop you thus preventing such a start-up. After all if you had a real choice then you would be able to choose an honest dealer. (And yes, I know there is some choice. But a cartel behaves almost identically to a monopoly. They are just as bad for the economy. Don't believe me, then design an engine that does not infringe on any patents. I do not believe it can be done, well not for an engine that is useful or anyone wants anyway.)
Capitalism is not any more to blame for this, than socialism is for the holocaust.

Re:Real-world conditions

[Anonymous Coward]

In other wards being a human being and owning/driving a vehicle.

Re:Real-world conditions

[Lumpy]

So magically I fixed the problem? Cool! I'm going to sell my magical tools! I'll make millions. And I cant drive any less overloaded with only 1 passenger in the car.
Oh and it's a known issue with ALL 8th gen civics and the FIT, well documented and there is even a lawsuit about it.

But let's not let facts get in the way, you're the expert.

Re:Real-world conditions

[Anonymous Coward]

Our American testing is a little more aggressive; lots of people get more than the EPA number, and some of the cars can just barely create enough torque to keep up with the EPA profile.

Re:Real-world conditions

[Pokey.Clyde]

I'm a hypermiler.

Stopped reading right there. It's assholes like you that make driving worse for everyone else.

Re:Real-world conditions

[SimonTheSoundMan]

The flaw is it has stupidly hard roll bars and coil overs, something that modern sporty hatchbacks seem to have. You need this camber (and toe) to bring stability back.

Re:Real-world conditions

[Maxwell]

Your limited knowledge of car suspension is risking your wife's life. At 80 mph your civic will understeer and roll over with any sudden steering input, such as an emergency lane change. You should put the cost savings from your mileage improvement into the funeral fund - those things are expensive you know.

Or it could be be you know more about suspension setups then Honda, who won the Indy 500 yesterday. Yeah, that's it. You should really write them a letter about their 'design flaw'.

Re:Real-world conditions

[Anonymous Coward]

Or it could be be you know more about suspension setups then Honda, who won the Indy 500 yesterday. Yeah, that's it. You should really write them a letter about their 'design flaw'.

Their engine won. Not their chassis.

Re:Real-world conditions

[L. J. Beauregard]

I certainly hope you don't draft trucks and avoid braking at the same time.

Re:Real-world conditions

[Anonymous Coward]

"Draft trucks"

So you are stealing from the truck drivers.

Re:Real-world conditions

[inasity_rules]

As far as I can tell, drafting trucks is pretty idiotic all by itself. You can't see where you're going, and in order for it to help (if you're too far back the turbulence may make things worse) you're so close that if he slams on breaks or hits something, you die.

Re:Real-world conditions

[Bengie]

MPG figures should reflect real world situations, not contrived situations.

Re:Real-world conditions

[Computershack]

That's all true, but manufacturers go to great lengths to inflate the figure. They disconnect the alternator, tape up cracks in the bodywork to improve airflow, remove wing mirrors(!), disconnect the brakes to reduce friction and use special oils in the engine to improve efficiency

Not in the EU testing.

Re:Real-world conditions

[Khyber]

If you need a negative camber for stability and you're not on a race track, you've fucked up design somewhere.

I've been working on vehicles for roughly 15 years and I've got roughly 400+K miles flawless driving record. The idiots with cambered tires tend to perform very poorly on drag race strips and drifting tracks, and lose control because of the reduced contact between the road and tires. It's the dumbest thing to do and the PROPER way to alleviate this is an a-frame sway bar with MacPherson (or similar) struts attached.

Re:Real-world conditions

[Anonymous Coward]

yes, honda's hive mind was equally active in setting up the fit and the
"honda" that one the indy 500. there are two major flaws with this thinking
- the chassis is made by delara, and
- andretti autosport owns the team that badges their delara "honda"

by the way if sponsorship makes any difference, why with the honda f1
team so terrible until they quit, and ross braun won the constructors title
the very next year?

Re:Real-world conditions

[Khyber]

"Or it could be be you know more about suspension setups then Honda, who won the Indy 500 yesterday."

Considering it's all turns in one direction, uh, no. Honda still knows jack shit about suspension setups. Their FIT is top-heavy and will roll on a whim. Their old 4x4 WAGON had one of the most horrible suspensions I've ever dealt with. The old CRX was like trying to ride a fixie on a garden gravel road. Even their motorcycles (like the older shadow 500) had shit suspensions and shocks.

Re:Real-world conditions

[nblender]

yeah; I remember Mythbusters tried this out... It didn't start to actually make any difference until they were something like 18" behind the truck... I really think only a "Hypermiler" would be stupid enough to actually do that.

Re:Real-world conditions

[Computershack]

Also set up wrong by the manufacturer. The 2007 honda civic has a highway MPG rating of 40mpg. I regularly get 44-46 while speeding after I fixed their design flaw in the rear end. they set the car with significant negative rear camber and with about 2 degrees of toe, I reset it to zero and zero and not only did fuel mileage numbers skyrocket by 10-15% but rear tire wear dropped to zero or undetectable.

Oh. Dear. So what you've done is make the cornering worse. Mind you given that US cars are a bit crap when it comes to bends you probably don't notice any difference.

Re:Real-world conditions

[nblender]

Exactly right. I have an offroad vehicle with air suspension... I can raise/lower the truck about 8 inches... At factory height; the truck drives normal... If I raise it just a few inches, the front axle rotates enough that driving it is like trying to hold on to a slippery eel.. It doesn't take much in terms of suspension changes to dramatically affect the handling of a vehicle. This is why there are properly engineered suspension _kits_ vs shoving blocks between spring/axle to make your truck look cool.

I drive around at factory height but raise the truck when I'm off road going 5mph.

Re:Real-world conditions

[Anonymous Coward]

Soon we'll have self-driving cars. Then you can drive a videogame car while commuting, to get your kicks. And get drunk and high!

Re:Real-world conditions

[Anonymous Coward]

Considering it's all turns in one direction, uh, no. Honda still knows jack shit about suspension setups.

Technically, Honda vehicles also won the previous two races, both road courses. One in Birmingham, and the other on the Indy Road course.

Re:Real-world conditions

[blue trane]

So, 3D-printed cars would be good for capitalism. But won't the capitalist car makers fight them tooth and nail? Like dealerships fight Tesla trying to sell direct to consumers? Capitalism is rife with perverse incentives and moral hazards. Slavery was eminently capitalist. Adam Smith thought that workers should have a right to sell their own labor; but capitalism, left to its pure self, won't respect that right. You need something higher than capitalism, like a government committed to the General Welfare.

Re:Real-world conditions

[funwithBSD]

You missed a step there. The Car makers are not fighting by competing, but by manipulating the "government committed to the General Welfare"

Without a powerful government to influence and have pass laws against selling cars directly, the big Car Makers would have to compete with Tesla.

Then again, Tesla only exists and can sell cars because another part of the "Government committed to the General Welfare" subsidizes their product, so they are not competing either, but lobbying the Government to pass laws to make them competitive.

Government is less effective the deeper it goes. Build roads? Sure. Micro regulate cars? Hmm....

Re:Real-world conditions

[KozmoStevnNaut]

A lawsuit does not magically make whatever it alleges true. It just means a lawyer managed to convince a judge to rule in his/his clients' favor.

Oddly enough, the Civic and Fit/Jazz are very popular vehicles here, yet no one has raised a stink about anything suspension-related. Funny that.

Re:Real-world conditions

[funwithBSD]

No, it helps smooth the truck's slip stream as well.

Re:Real-world conditions

[whoever57]

use decent fuel,

If you mean "use high-octane fuel", unless your car is designed for high-octane fuel, then all you are doing is wasting money.

Re:Real-world conditions

[funwithBSD]

Oh yeah. Before I put modern progressive springs on it, the 75 CB550 was like a squirrelly jackhammer.

Re:Real-world conditions

[Anonymous Coward]

So you've actually made your car significantly less safe, all for the sake of a few MPG. Congratulations, I hope you're proud.

One day under-responsive steering and the next day over-responsive. His wife drives it and his plan is going well.

Re:Real-world conditions

[chihowa]

Hypermiling is as far from driving safely and responsibly as is the videogame style driving you're imagining. It's just as antisocial, self-centered, and dangerous, but the goal is saving gas and not arriving sooner (or having fun or whatever).

Re:Real-world conditions

[Anonymous Coward]

Nothing you said has any bearing on advertised gas mileage. Nobody has patented gas mileage number calculations.

I'm guessing where you're going with this is the idea that without patents, everybody would design their cars identically to maximum gas efficiency, and we'd all know it was identical, and thus there would be no need to exaggerate. I think you'll find a lot of things besides patents that would do that, not least of which is borne out by the fact that companies put out multiple vehicles with multiple fuel efficiency ratings, despite having access to all the same tech.

A flaw it capitalism is that it resists its own proper functioning. For instance, ideal capitalism requires perfect information. Perfect information is always going to be unachievable, but as implemented capitalism doesn't even discourage people from working *against* perfect information, as they do by generating and propagating misleading gas mileage numbers.

An example more in your wheelhouse is that monopolies are the natural result of a successful organization in a market that contains barriers to entry, whether they are natural (like signal distribution eg. cable, fibre-optic, electrical) or artificial (patents, price dumping, product tying, buying up the entire raw materials market a la deBeers or Apple, etc.).

Those categories obviously tend to overlap with where we apply lots of regulation in practice.

Anyway, I'm guessing you think the root cause is that mileage-improving technologies are patented and thus unshared. I think you'll find that there are tradeoffs made even within a company.

Re:Real-world conditions

[Anonymous Coward]

If it helps you feel any better, I just drive "responsibly". Plan ahead, don't take off like a bat out of hell, predict, and be courteous to other drivers. It's no good to be the last person sneaking through a yellow light because you were going 34 in a 40 zone, for example.

Rather than being a person who is still being a selfish prick (driving differently in ways that may be detrimental to the overall flow of traffic in order to maximize ONLY your fuel consumption efficiency), the best attitude to take is to drive in such a way that helps you without impeding others in a manner that directly causes them to lose efficiency - like 34 in a 40 zone and squeaking through the yellow to leave a long line idling at the red behind you.

As for making driving worse for everybody else, it's all a point of view. If you stay behind me and I'm not obstructed by something stupid too often, you will hit pretty much every light green for several miles. You will save your brakes from an early death and you will get anywhere from 10-30% more fuel efficiency. The worst that will happen is you'll spend about two minutes longer on the drive.

But if you're the kind of person who prefers to slam the gas when the light turns green, weave around everybody to get to the front... Well, that's fine too. I'll still be pulling up behind you at most red lights and worst case on the same route, I've arrived from an hour trip a whole three and a half minutes behind the person who drive like a maniac to get there faster. The difference is they get about 20% less fuel efficiency than advertised and I get about 20% more than advertised, so I pocket several hundred a year. My time loss to savings ratio means I get paid about 200 an hour to drive like that.

Re:Real-world conditions

[blue trane]

If government didn't exist or didn't regulate, capitalism would create it and create the regulations necessary to protect its players. Example: the private banking system evolved centralization on its own long before the Fed. J. P. Morgan ended the Panic of 1907 by creating his own "clearinghouse certificates" which supplied needed liquidity to the system. But even capitalists recognized it probably wasn't a good idea to rely on Morgan to get them out of another crisis; Morgan, being a profit-minded capitalist, was in a position where he could help his friends and hurt his enemies, take advantage of competitors' weakness to buy them at a ridiculously low price, etc. The Fed, being non-profit (returning its profits to the Treasury each year), was a better solution because it could help even Morgan's enemies in a Panic by supplying necessary liquidity.

If the government didn't enforce patents, the moral hazards and perverse incentives of capitalism would create ways. Like the RIAA/MPAA manipulate torrents to introduce fake downloads, etc.

One solution to capitalism is to fuyll democratize the money supply. Free individuals from having to play the capitalist game by providing a Basic Income to anyone who wants it. Leave business alone to innovate in their way, but encourage individuals to innovate disruptively on their own. Hold challenges to stimulate the natural instinct for creativity and wonder in each of us.

So individuals can come up with 3D-printed car designs, and business could refine them. Labor costs should go down as businesses automate more and outsource innovation to challenges. Inflation shouldn't increase because there would be no wage-price spiral, individuals on a Basic Income could work at Walmart if they wanted to, so Walmart wouldn't have to raise its prices.

Even if inflation became a problem, we can deal with it by indexing everything to inflation. Since the relationships between prices and cash flows don't change, inflation becomes invisible. Israel used this method for decades; with modern automation, the "drag" that led them to abandon it can be eliminated, so that the indexing is seamless.

Re:Real-world conditions

[TubeSteak]

This story is about European standards which are a bit wacky, but I know they get spot-checked in the US. Hyundai paid out a huge settlement for (apparently honestly) screwing up the testing.

The issue isn't the testing, it's the testing standards.
The standards don't require a car in showroom condition, there's lots of wiggle room for the manufacturers to gimmick the test.

Re:Real-world conditions

[Rei]

That's the key here. EU mileage figures are rated based on the NEDC cycle, which gives about 15% better mileage figures than the EPA combined cycle. Given that this guy is saying real world is 19% worse than the NEDC, then that's a pretty good testament to the EPA combined cycle.

At least the NEDC is better than the laughable Japanese 10-15 cycle, which gives figures about 10-15% even better than the NEDC.

It's one thing that drives me crazy when Americans point out to cars overseas and say, "Look, how come they get cars that are so much better mileage than ours?" The truth is, there's not actually all that much difference. UK car figures are often even worse because they're usually reported in miles per imperial gallon, which gives an extra 20% boost to mpg figures. On top of that, a large percent of European cars are diesels. While it's fair to compare diesels to gasoline cars when comparing what ou have to pay for fuel, it's not so for an environmental comparison. Diesel is 10-15% denser than gasoline; a gallon of diesel represents 10-15% more oil consumption and emits roughly correspondingly more CO2 than a gallon of gasoline. If one cares about CO2, the best approach is to ignore MPG and look at g/100km figures, which are almost always based on the same cycle (NEDC) and take into account differences in the fuel.

Re:Real-world conditions

[bobjr94]

Here in the US, mileage estimates are usually slightly less that real world. Most every car Ive owned have gotten better that the epa estimate. Our current cars are a 04 subaru wrx sti, it's rated 16-22 under the new ratings. I average 24 in mixed driving and get 27 on long freeway trips. My wife just got an 15 wrx, rated 21-28, she has averaged 27 in mixed driving and over 32 on one long trip.

Re:Real-world conditions

[amorsen]

In several markets you can buy petrol which is supposed to reduce losses in the engine. It has the same octane rating as regular petrol.

Whether it actually works I do not know. I like that fuel is a commodity, I resent the recent attempts at changing that. I wonder if I will be able to go to charging stations with special long-running electrons in ten years...

Re:Real-world conditions

[Chrisq]

All the tricks you mention would only improve the number by a fairly small percentarge, likely low double digits.

You are claiming that your normal usage doubles your fuel consumption. That suggests that most of the problem is in your driving style.

No its down to my normal commute being short (engine cold most of the time), stop-start due to traffic, and over a lot of hills. I've had to refine my style to mean that I only reduce my mpg from 54 to 35 compared to a long straight drive.

Re:Real-world conditions

[Smauler]

I'm a hypermiler. I get 51 mpg out of my diesel minivan, But I have to work really hard at it, drive slowly, draft trucks, avoid braking, coast and engine-brake whenever I can.

Engine braking is just as bad for fuel efficiency as ordinary braking is. The reason it's recommended is to preserve brake pads (and prevent brake overheating in extreme cases, like trucks down long hills), not to increase mpg.

When you say engine braking, I assume you mean deliberately changing down one or two gears to increase engine braking, rather than using the gear you were in. Taking the car entirely out of gear (or dropping the clutch) when braking is obviously bad for mpg because the car uses fuel to maintain tickover as you are braking, not to mention the additional strain put on the brakes.

Note : this is true for (most) modern cars with fuel injectors, which will not use any fuel when in gear with no accelerator pedal application. Older cars with carburetors will use fuel depending on their revs even with no accelerator pedal application. So, for optimum mpg for older cars, it probably is best to coast in neutral at tickover down hills just using the brakes. However, this is not very good for the brakes. You could turn the engine off altogether down long hills in old cars for even better mpg.... this is most definitely extremely not recommended, for lots of reasons.

Re:Real-world conditions

[mjwx]

Under-inflated tires, lousy fuel, ignored maintenance, rapid acceleration, more than one occupant / actual cargo, stop-and-go traffic, air pollution, air pressure variation, air temperature variation, elevation variation...

And these are just a few of the things that would cause your "official" MPG figures to deviate from observations.

In other words, outside laboratory conditions.

I thought it was common knowledge to ignore official fuel efficiency figures. Manufacturers will lie out of their backsides to meet emissions targets and get their cars into a lower tax bracket. Common knowledge seems to be as common as common sense.

I haven't read the What Car article, but I'm willing to bet small engined turbo's are amongst the worst offenders. Manufacturers will try to get as much of the test done before turbo engagement because once the turbo engages, fuel usage goes through the roof. A 1.4L turbo doesn't use much fuel until it hits the turbo where it will easily out drink a 2L Naturally Aspirated engine. They might even play with the boost pressure on the test car.

Re:Real-world conditions

[mjwx]

It's one thing that drives me crazy when Americans point out to cars overseas and say, "Look, how come they get cars that are so much better mileage than ours?" The truth is,

The truth is, that Europeans generally choose more fuel efficient cars to drive. Huge, un-aerodynamic, heavy, view-blocking SUV mum-tanks with massive engines to overcompensate aren't popular. Europeans will tend to drive sub-2L cars. The average European will spend less on petrol per KM than the average American despite petrol costing almost twice as much in some countries.

However in comparisons between cars made for the American market and cars made for the European market, the European engines will produce more power for less fuel with less displacement. I dont know how Americans get a whopping 270 KW out of a 6.2L V8 when Europe gets a meagre 350Kw out of a 4.5L V8 and that's considered weak. I can get 270 KW out of a 12 yr old Nissan i4 turbo (of course that would be silly, the car its in is very light so all 270KW would do is shred the back tyres).

Re:Real-world conditions

[Khyber]

Both not very challenging to any suspension on the planet.

Re:Real-world conditions

[funwithBSD]

Oh gods. a rant.

And not once addressing the actual issue: government is a problem to be managed, not a solution.

Basic Income. Please, if want charity, make it local. You provide a basic income to as many people as you want to and earn it yourself. Don't drag me into it. Basic wage would just disincentivize people to work. Re: Roman Corn Dole. It has been tried before

Exception: If we get to the point where entire industries can be automated from start to end, basic wage is workable because the cost of labor is near zero.

We are a few hundred years from that, I think.

Re:Real-world conditions

[Askmum]

Not true. The NEDC has one cycle going up to 120 km/h, but even driving with a maximum of 90 km/h does not make one reach the official MPG figures. The problem is more that the NEDC is an artificial measurement created in an era that cars were lighter and less powerful. It is not an accurate representation of how people drive.

Re:Real-world conditions

[KozmoStevnNaut]

We're talking a few degrees of negative camber, not massive "stanced" or "slammed" or "demon camber" or whicher idiotic thing mouthbreathers do to their cars these days.

A little bit of negative rear camber significantly aids cornering stability. Too much hurts straight line stability, but a bit of additional toe-in can mitigate this. Too little will hurt corner stability. For a street-driven car where tire wear is also a concern, a couple of degrees is ideal.

Re:Real-world conditions

[AmiMoJo]

That article you linked to is nonsense. The EU tests require production spec cars, unmodified and operated by staff at the test centre. Occasionally they buy random examples off the forecourt just to check that nothing has been quietly changed after the test was done.

It is true that manufacturers try to game the tests buy designing their cars to do well in them, rather than in real world conditions.

Re:Real-world conditions

[AmiMoJo]

The fact that you get "no measurable tyre wear" on the rear wheels should be screaming something at you. It tells you that they are not making adequate contact with the surface of the road and holding your car firm to it as you corner or brake/accelerate. You reduced the handling performance and safety of your car, making it more prone to lose traction on the rear wheels and skid.

Your wife is in serious danger if she races to work at 80mph every day. If she is forced to brake hard or enters a corner a bit too quick she could have a serious accident.

Re:Real-world conditions

[Chrisq]

That article you linked to is nonsense. The EU tests require production spec cars, unmodified and operated by staff at the test centre.

Its on the BBC site as well (Also multiple other sites, google search. The claim is they find loopholes that don't count as modification.

Re:Real-world conditions

[Stuarticus]

Re: Roman Corn Dole. It has been tried before

That's why people will never fly either, Icarus already tried it and it didn't work.

Re:Real-world conditions

[funwithBSD]

Icarus is a myth, Rome was real.

Care to find any current/recent examples of your idea?

The Swiss rejected it last week, and Iran is the only country that is doing it currently.

So any other attempts have failed, unless you are thinking of a theocratic dictatorship to go along with it.

Re:Real-world conditions

[Shirley Marquez]

Europeans are also offered more fuel efficient cars to buy. Many car models offer a variety of engine options elsewhere, but only the largest one is sold in the US. And companies make smaller car models that are sold elsewhere but not in the US.

VW is a good example; compare the range of offerings on the US site of www.vw.com to the ones on www.volkswagen.de or www.volkswagen.co.uk to see the contrast. The smallest car they sell in the US is the Golf but there are two smaller models, the up! and the Polo, that you can get in Europe. In the UK the Jetta is offered with either a 1.4L gas engine or a 1.6L TDI, but in the US the choices are 2.0L gas and 2.0L TDI. (I didn't compare the Golf because that car is currently about to replaced with an updated one in the US and info on the new version is not yet available on vw.com.) On the other hand, the Jetta Hybrid (1.4L gas engine plus electric boost) is offered in the US (and Germany, of course) but not in the UK.

Re:Real-world conditions

[Shirley Marquez]

In the early days of EPA testing, some car companies put special oil in the cars to improve the mileage ratings. Then somebody said "if this special oil works, why not market it to everybody?" They did, and the result was that everybody's gas mileage improved by 2-5%; just about all the motor oil you can buy now has mileage-enhancing additives.

Re:Real-world conditions

[Stuarticus]

How about all the people who already have more than money than they could ever need but still go to work every day because they want something to do?

Re:Real-world conditions

[funwithBSD]

What about them?

They don't seem germane to the discussion. They would be, by definition of "more money then they could ever need" be 1% or less of the population.

So universal social welfare because 1% of the population will still work?

Honestly, not sure if that is what you meant, as your logic does not seem to follow.

Re:Real-world conditions

[Stuarticus]

So only that 1% would be willing, coincidentally the same 1% that do anyway. I think you may be suffering from a common condition known as "ideological blindness".

What's that in KPL?

[Anonymous Coward]

International standards please...

Re:What's that in KPL?

[jspayne]

Your concern might be less of a troll if you knew that the standard metric measure for fuel economy isn't km/l, but rather l / 100km.

Re:What's that in KPL?

[Anonymous Coward]

That's the fun of standards, there's so many to choose from.

From Wikipedia: http://en.wikipedia.org/wiki/Fuel_efficiency (for what it's worth)

The fuel efficiency of vehicles can be expressed in more ways:

        Fuel consumption is the amount of fuel used per unit distance; for example, litres per 100 kilometres (L/100 km). In this case, the lower the value, the more economic a vehicle is (the less fuel it needs to travel a certain distance); this is the measure generally used across Europe (except the UK, Denmark and The Netherlands - see below), New Zealand, Australia and Canada. Also in Uruguay, Paraguay, Guatemala, Colombia, China, and Madagascar.[citation needed], as also in post-Soviet space.

        Fuel economy is the distance travelled per unit volume of fuel used; for example, kilometres per litre (km/L) or miles per gallon (MPG), where 1 MPG (imperial) 0.354006 km/L. In this case, the higher the value, the more economic a vehicle is (the more distance it can travel with a certain volume of fuel). This measure is popular in the USA and the UK (mpg), but in Europe, India, Japan, South Korea and Latin America the metric unit km/L is used instead.

Re:What's that in KPL?

[AthanasiusKircher]

Your concern might be less of a troll if you knew that the standard metric measure for fuel economy isn't km/l, but rather l / 100km.

While km/L is less common, it certainly does appear as an alternative measure in many countries, particularly to allow people to compare it to mpg metrics (as the GP was suggesting here, since the title of this story is about "MPG"). You are correct that in many countries, L/100km is standard.

Before we get the standard debate about this crap that comes up every time this topic comes around, let me just point out that the reciprocal relationship between these two measurements doesn't mean one is "more correct" than the other. Rather, both will give intuitive results for different questions or given different constraints.

For example, if you're buying a car primarily for commuting, gas consumption per distance (e.g., L/100km) will give you an intuitive sense of your fuel cost, since your daily distance is relatively fixed. If your L/100km doubles, your fuel cost for fixed commutes will double.

On the other hand, if you're buying a car primarily for occasional longer trips and not using it for regular commuting, distance per gas unit (e.g., mpg or km/L) will give you a more intuitive sense of how far you'll be able to travel with the same gas budget. People buying a car only for occasional trips probably are more likely to care about how far they can go with a given amount of fuel rather than how the fuel cost will vary for a fixed distance. If your MPG doubles, you can go twice as far with the same amount of fuel.

Different metrics are useful for different things. These two have a very clear relationship, but when non-math-literate people are comparing the raw numbers, one can be better than another in making decisions depending on the situation.

Re:What's that in KPL?

[Anonymous Coward]

km/L cannot be compared to MPG. You need to convert it first. Both km/L and L/100km require exactly 1 mathematical operation to convert.

And L/100km is more correct than a reciprocal unit. Just because you can find one use case for contaminated milk, it doesn't make it equal to normal milk.

Re:What's that in KPL?

[Hognoxious]

If a bunch of MBAs say so it must be true!

Re:What's that in KPL?

[Anonymous Coward]

Honestly, as a driver, I calculate how many kilometers per liter that I get. I stop at the gas/petrol station, I fill up the car, I reset my odometer, I drive. At about half a tank, I go back to the gas station, fill the tank, compare the kilometers driven to the amount of petrol put in the gas tank and do some math.

It is easy to see that I get roughly 10 kilometers for every liter of gas that I put into my car.

In short, it is mentally and more intuitively easier to just do kilometers per liter rather than liters per 100km... despite liters per 100km being a simple mathematical transformation.

Re:What's that in KPL?

[AthanasiusKircher]

km/L cannot be compared to MPG. You need to convert it first.

Umm, duh. You think we're all idiots around here? However -- you can make the same TYPES of comparisons using km/L and MPG. You can't make the same TYPES of comparisons between MPG and L/100km. In this sense, MPG and km/L are SIMILAR kinds of measurements, and thus are COMPARABLE for similar types of questions. If you're trying to come up with a measurement that tells you the same information as MPG, km/L is it... not the alternative.

And L/100km is more correct than a reciprocal unit. Just because you can find one use case for contaminated milk, it doesn't make it equal to normal milk.

Hilarious. Your linked article could just as well be used an example of the contrived use case. See my comment on an old article here.

My level of surprise...

[Anonymous Coward]

...is well under 9000.

No fuel economy figures are going be right

[Anonymous Coward]

Isn't the more important thing that the all the cars figures are comparable.

Re:No fuel economy figures are going be right

[Anonymous Coward]

Isn't the more important thing that the all the cars figures are comparable.

Except that odds are good they're not. The tricks used to get one vehicle up to 50mpg may not work on another vehicle (one being a car and another a truck*). The whole reason then to have accurate figures is precisely that it's the only way to make the figures comparable. The real issue, of course, isn't that the figures are accurate. It's whether vehicles manufacturers are intentionally manipulating the numbers precisely because people like you believe that the various cheats they use produce comparable numbers and hence they can commit a clear deception to get you to buy their vehicle over another. Ie, the issue is fundamentally whether there's fraud at play.

*Removing parts of a truck may more doable and you can add a bit of rigid material to greatly increase the aerodynamic performance of a truck vs an already aerodynamic car. So, off-hand, any truck-like car can cheat more than a car-like truck. That doesn't even get into even more fiendish stuff (some aluminum components, diesel instead of gasoline, entirely missing large parts of the engine that'll destroy the engine in a few hours to bring the weight down, etc).

Re:No fuel economy figures are going be right

[jtownatpunk.net]

Exactly. If they've got good precision, the information is still useful. You can tell that Car A uses significantly more fuel per mile (or whatever the heck a "kilometer" is) than Car B.

Re:No fuel economy figures are going be right

[Legendary Teeth]

Not if you are trying to estimate the TCO of a car. For example, it matters if you are trying to answer the question "Is it cheaper in the long run to buy this more expensive, more fuel efficient car, compared to this cheaper less efficient one?"

Re:No fuel economy figures are going be right

[InvalidError]

How much MPG inflation was applied to "Car A" vs "Car B" ?

If Car A scores 50MPG using a tweaked evaluation rebuild while Car B scores 40MPG in all-stock off-the-assembly-line configuration, there is a fairly good chance Car B may actually fare better under real-world conditions than a stock version of Car A.

It is a bit like F1 racing: under ideal conditions, the engine would be designed to just barely not fall apart until the last race of the season is over. For an MPG evaluation, the car only needs to last long enough to complete the tests without any obvious signs of problems and I bet there are many inventive ways to inflate MPG figures using that.

Re:No fuel economy figures are going be right

[ceoyoyo]

An inaccurate but precise measure is great if it's consistently inaccurate. But if it's consistently inaccurate, why not just measure the inaccuracy and correct all the values?

Because inaccurate measurements are rarely consistently so.

Re:No fuel economy figures are going be right

[Anonymous Coward]

whatever the heck a "kilometer" is

Why don't you go ask your entirely-metric military, Ameritard?

Re:No fuel economy figures are going be right

[Anonymous Coward]

How much MPG inflation was applied to "Car A" vs "Car B" ?

If Car A scores 50MPG using a tweaked evaluation rebuild while Car B scores 40MPG in all-stock off-the-assembly-line configuration, there is a fairly good chance Car B may actually fare better under real-world conditions than a stock version of Car A.

If different cars can be inflated differently, then the test is not sufficiently standardized. The point of a standard test is that I can buy one of my competitor's cars, run it through the test, and then destroy them in the media if their fuel efficiency is 20% below what they advertise. This is different from the complaint in the article, which is that the standardized test does not reflect real world driving. Unfortunately, real world driving is a little different for every driver, so you could just as well say their real world driving test is also going to be inaccurate.

Re:No fuel economy figures are going be right

[MadKeithV]

An inaccurate but precise measure is great if it's consistently inaccurate. But if it's consistently inaccurate, why not just measure the inaccuracy and correct all the values?

Because inaccurate measurements are rarely consistently so.

The test isn't claimed to be inaccurate, it's claimed to be non-representative of real-world usage.

Re:No fuel economy figures are going be right

[ceoyoyo]

A test not producing results that reflect what it purports to be measuring is kinda the definition of inaccurate. Perhaps you're confusing accuracy and precision?

Re:No fuel economy figures are going be right

[timeOday]

Consumer Reports buys cars right off the lot, that's the right way to do it.

Re:No fuel economy figures are going be right

[AmiMoJo]

They are required to test production model cars with no modifications. No tweaked rebuilds allowed.

Re:No fuel economy figures are going be right

[Anonymous Coward]

..per mile (or whatever the heck a "kilometer" is) than..

Herp.

Herp-a-derp. Mister Witticism is in the house.

Yes, the testing standards need to change!

[Anonymous Coward]

The testing standards need to change to reflect real life usage not laboratory engine and drag testing. There is another website called www.fuelly.com that you can track your usage and compare it to others. I purchased a Scion IQ that claimed 4.5 L/100km on the highway. The lowest it got was 6.5L/100km. Now that's an error of 44%! Not many people have purchased this micro car because the whole point is to save money on fuel but it has the same fuel economy as a 4 door car.

We knew the gist already

[elwinc]

We pretty much already knew that the MPG we saw on the sticker was higher than the MPG we would actually be getting. Hence the phrase "your mileage may vary."

But we also know that the sticker MPG numbers are good for comparing among similar cars, and that's mostly how we use the sticker MPGs. Kudos and thanks to 'What Car?' for calculating the 19% offset figure. I wonder if they could tell us how the offset varies among different types of cars. Maybe SUVs vs econoboxes vs sports cars have somewhat different offsets.

BTW, I would bet that different driving styles, lead foot vs hypermiling, makes a bigger differnece than the 19% calculated by 'What Car?'

Re:We knew the gist already

[Anonymous Coward]

You're on a website for programmers and you don't know the difference between an offset and a factor? For shame.

Re:We knew the gist already

[Electricity Likes Me]

The only important thing is whether the figures can reverse on you. If it's an across the board reduction, who cares? I'd be way more interested if it was possible for the relative efficiency of two vehicles to actually switch around.

Re:We knew the gist already

[Anonymous Coward]

> But we also know that the sticker MPG numbers are good for comparing among similar cars,

No, you don't know that. You assume that.

When the benchmark doesn't test the things you care about then you can not count on a linear correspondence between the benchmark performance and performance on what you want to measure.

Think of it this way - the manufacturers are "teaching to the test" when they design their cars now. A student who only memorizes the test questions isn't going to have a real knowledge of anything that isn't on the test.

Re:We knew the gist already

[Anonymous Coward]

I think I'm going to disagree. I would say the listed MPG numbers are suitable for comparison.

From what I recall, the reason that the MPG sticker numbers are off is that the tests are performed on a dynamometer. This accomplishes the need to get a standard, comparable test situation and it's probably the easiest answer to getting standardized numbers. However it does not reflect real-world driving conditions which degrade fuel economy on average.

So long as every vehicle is getting testing on a comparable dyno regime, those MPG numbers are adequate for determining that "Car X will get me better fuel economy than Car Y".

However it has long been known that the sticker MPG figures are highly optimistic for any real-world driver.

taxes will lead to kludges

[Anonymous Coward]

Various European nations tax cars based on calculated mpg. also, it is useful in swaying fuel conscious customers, where gasoline is about $8/gallon. In America, the EPA numbers tend to be close to real world mpg, and if people want to get high mpg, avoid the SUV, or go straight for the Prius. The Prius is that good.

Re:taxes will lead to kludges

[Z00L00K]

Except that the Prius costs more energy to make than many vehicles with a higher fuel consumption.

Re:taxes will lead to kludges

[Justpin]

The Prius is actually a confidence trick. I know taxi drivers who get about the same MPG as they did in their old Toyota corollas, while being considerably less pleasant to drive as the prius is hypermilled with a thin skin and very little sound insulation.

Re:taxes will lead to kludges

[TClevenger]

Except that the Prius costs more energy to make than many vehicles with a higher fuel consumption.

I'm willing to bet that it doesn't take much more energy than other cars its weight.

Re:taxes will lead to kludges

[Anonymous Coward]

which is irrelevant because 90% of a car's energy use over its lifetime is its fuel use.
with a Prius that percentage is lower, as it takes more energy to construct, and uses less energy to use.

provided you drive it enough, its total lifetime energy use is still lower, despite the higher initial costs.

Re:taxes will lead to kludges

[MightyYar]

I'm suspicious of the Prius simply because they don't offer a non-hybrid version. The aerodynamics shape and narrow tires seem well-suited to fuel economy no matter what the engine. The hybrid Camry is an economic non-starter for my use case.

Re:taxes will lead to kludges

[Bertie]

Pretty much, yeah. Toyota designed an Atkinson cycle engine, which is much more efficient than the traditional Otto cycle. The problem is that it doesn't produce much torque, meaning that it doesn't take off as quickly as people would like. So they added an electric booster to make up the torque shortfall. The fuel savings from running on battery are minimal - the internal combustion engine usually kicks in within seconds of setting off, and stays on unless coasting. Conventional cars don't use fuel when coasting anyway, so you don't save anything there, and in fact lose a bit into recharging the batteries.

Re:taxes will lead to kludges

[Lumpy]

If you ignore the lithium ion battery pack? yes.

Re:taxes will lead to kludges

[InvalidError]

Toyota, Honda and Ford got sued by plenty of people about overstated fuel efficiency - particularly in colder states and Canada where many complain that their hybrid car has worse real-world MPG than plain ICE cars.

Re:taxes will lead to kludges

[L. J. Beauregard]

The Prius battery is NiMH. Some other hybrids might use Li-ion.

Re:taxes will lead to kludges

[Computershack]

Various European nations tax cars based on calculated mpg.

No they don't, they tax them based on emissions which has little to do with MPG or engine capacity.

Re:taxes will lead to kludges

[Anonymous Coward]

*Slightly* more energy. That extra energy used is made up for more than ten times over by energy saved during operations.

Re:taxes will lead to kludges

[Anonymous Coward]

You're referring to an exceedingly small number of cases here. If you look at fuelly's numbers, only 55 out of 1879 Corollas tracked average more than 40 MPG (2.9%), while only 178 out of all 2930 Prii tracked get *less than* 40 MPG (6%). In the overwhelming majority of cases, the Prius gets better fuel efficiency than Corollas.

That, and the Prius' chief advantage is in city driving, which taxis operate in virtually exclusively. Since you're claiming Corollas beat them in their home environment, I call bullshit on your argument.

Re:taxes will lead to kludges

[Anonymous Coward]

Coasting = driving while in neutral which means the engine will use fuel to keep the engine ticking over. If you're driving downhill in gear and don't use the accelerator, you will be using "engine braking" and the computer will turn off the fuel supply - this is also called DFCO - de-aceleration fuel cut off - however this will waste kinetic energy unless you need to keep slow for speed limits. DFCO don't occur in engines with a carburettor.

Re:taxes will lead to kludges

[LinuxIsGarbage]

You're referring to an exceedingly small number of cases here. If you look at fuelly's numbers, only 55 out of 1879 Corollas tracked average more than 40 MPG (2.9%), while only 178 out of all 2930 Prii tracked get *less than* 40 MPG (6%). In the overwhelming majority of cases, the Prius gets better fuel efficiency than Corollas.

That, and the Prius' chief advantage is in city driving, which taxis operate in virtually exclusively. Since you're claiming Corollas beat them in their home environment, I call bullshit on your argument.

Not just city driving, but taxis do a lot more idling and waiting than a normal passenger car.

Stranger things have happened. Initially the city of Toronto failed to see as large of savings on Hybrid transit buses (seeing 10-20% vs. promised 20-30%), largely because they operated on suburban routes instead of stop and go urban routes.

http://www.theglobeandmail.com...

Re:taxes will lead to kludges

[petermgreen]

I dunno about the rest of europe but here in the UK car tax for ordinary cars registered since 1 march 2001* is determined from official CO2 emmision figures. The ammount of CO2 that comes out of the exhaust is almost directly proportional to the ammount of carbon in the fuel that goes from the tank to the engine**. I don't know if they directly measure the CO2 or just calculate it from the fuel input but either way it isn't going to make a massive difference.

* Older cars and new cars for which official CO2 figures are not available (scratch built custom cars and such) are taxed based on engine size. Very old cars are classed as historic vehicles and exempt from road tax.
** Carbon that comes out in any form other than CO2 is bad since it represents incomplete combustion and can be a nasty polloutant in it's own right.

Lower?

[countach]

Usually I think of lower figures as better. Especially in the UK with litres / 100km.

Re:Lower?

[Anonymous Coward]

saying "higher consumption" would certainly have been clearer. Here in NL we use a mix of km / l and l / 100km.

Re:Lower?

[Anonymous Coward]

mpg is "miles per gallon" -- lower is bad.

(also, I've never seen anyone actually use L/100km in the UK.... yes it's a standard but when you measure distances in miles on the road, it's a leap to far for most people to turn that into km for any measurement. I've rarely ever been able to get people to talk about fuel economy in the UK and I suspect this is in part due to the inability to informally measure fuel economy / fuel consumption because of the half-arsed conversion to the metric system)

Re:Lower?

[Justpin]

Except the Yanks have smaller gallons 3.78 litres vs 4,54litres. While a UK and Yank litre is the same 1000ml/cc

Re:Lower?

[Anonymous Coward]

I take offense to the comment that we yanks have smaller... oh wait you said gallons. That's ok.

Re:Lower?

[ArcadeMan]

the half-arsed conversion to the metric system

In that aspect, Canada is similar to the UK.

Re:Lower?

[LinuxIsGarbage]

Except the Yanks have smaller gallons 3.78 litres vs 4,54litres.

While a UK and Yank litre is the same 1000ml/cc

It's worse in Canada. Before Metrication, a gallon in Canada was the 4.54L Imperial gallon. And unless clarified, an unspecified gallon is still (supposed to be) assumed to be a Imperial Gallon. NRCan fuel consumption ratings are given in L/100lm, with ImpMPG still on the sticker for old farts. TV ads still push "MPG" ratings, and a lot of people still report their fuel economy in MPG even though distances aren't registered in miles, nor fuel sold in gallons (even young people who never bought gas in gallons!) It's even worse when they insist on using obsolete (for this country) units, yet don't even know which gallon they are using. In other cases they are too stupid to understand why Canadian MPG ratings are 20% larger than US MPG ratings.

Re:Lower?

[znrt]

mpg is "miles per gallon"

thank you. i already missed an inflamated post about wtf "mpg" should mean.

now that i know, i'm still struggling to understand why this should be posted on a tech category, and why the fuck should i care about how much drivers have to pay for happily keeping on polluting our planet. ah, slashdot! hang them all!

This is not new news

[knightar]

We all knew from previous reports, even in the US, that car manufactures will cheat and use "perfect conditions" and also gut the car of anything they can get rid of to decrease the weight and increase the MPG. Why are governments not requiring actual roadway numbers with an actual car as it comes out of the lot? Because lobbyists from the car manufacturers prevented it; Ether way I've always looked at the MPG and subtracted 20% from it.

Re:This is not new news

[nbsr]

Not the same. US/EPA rules attempt to model a "real life" drive cycle at the cost of getting more subjective numbers. In Europe, the rules are more synthetic so there is less cheating but all numbers are overoptimistic.

Re:This is not new news

[confused one]

To add to this... US EPA has changed the testing cycle twice in recent memory. Once to improve the numbers in general -- making the result more closely match real-world city driving conditions. Once to better accommodate hybrid models which were returning unrealistically high numbers in the standard test(s).

watch the program on 5th gear

[lkcl]

before making *any* judgement you *need* to watch the program on 5th gear which covers exactly this question in some detail. basically the test was designed originally for people driving sensibly, and it was designed i think well over 20 possibly even 30 years ago. so it has a very *very* gentle acceleration and deceleration curve. gentle acceleration because that is not only fuel-efficient but also the cars of that time simply could not accelerate that much, and gentle braking because again that is more fuel-efficient but also because if you had drum brakes they would overheat.

people no longer drive sensibly: they are more aggressive with other drivers (not keeping a safe distance), they put their foot down hard on the accelerator and they put their foot down hard on the brake. also as the cars are more reliable they tend to not maintain them properly: until i watched another program on 5th gear about how badly old oil affects fuel economy and the lifetime of the engine i had absolutely no intention of changing oil regularly in the decade-year-old cars i buy.

so, in effect, people should stop complaining and start driving in more fuel-efficient ways... *regardless* of how aggressive the person behind them gets when they set off from the lights at the same acceleration rate as a 40 tonne cargo lorry. that's the other person's problem.

Re:watch the program on 5th gear

[rolfwind]

and it was designed i think well over 20 possibly even 30 years ago. so it has a very *very* gentle acceleration and deceleration curve. gentle acceleration because that is not only fuel-efficient but also the cars of that time simply could not accelerate that much...

WTF are you blabbering on about? Cars from 1980 or 1990 could not accelerate that much?

You must be a young kid or something, but not everything before your time was primitive by virtue of you not having come along yet.

Re:watch the program on 5th gear

[Anonymous Coward]

He should watch the documentary "Grease" to see how people drove back in ye olden days :D

Re:watch the program on 5th gear

[Anonymous Coward]

Since 1960, yearly traffic deaths have gone from 8000 down to about 2000 currently.

You make some wild assumptions, but the figures suggest people are driving less reckless then before.

Re:watch the program on 5th gear

[Anonymous Coward]

or perhaps cars are that much safer?

Re:watch the program on 5th gear

[MightyYar]

That's a tough correlation to make. Cars and roads are also safer now, and lifesaving techniques have improved.

Re: watch the program on 5th gear

[Anonymous Coward]

Wtf, what country? The us kills 30,000+ a year in cars, mow down 4000 peds, and take out 600 cyclists. Every year.

Re: watch the program on 5th gear

[Anonymous Coward]

Article is about the UK so I used UK data.

Re:watch the program on 5th gear

[Captain_Chaos]

people no longer drive sensibly

[citation needed]

Re:watch the program on 5th gear

[Captain_Chaos]

people no longer drive sensibly: they are more aggressive with other drivers (not keeping a safe distance)

Is that why traffic deaths have consistently gone down since 20 or 30 years ago? - Killed_on_British_Roads.png

Re: watch the program on 5th gear

[ArcadeMan]

With these statistics, it means riding a bicycle is safer than driving a Hummer.

Re:watch the program on 5th gear

[wiredlogic]

I think GP was referring to gutless European econoboxes.

Re:watch the program on 5th gear

[Anonymous Coward]

Some people drove sports cars in the 70s and 80s, but most people drove heavy-ass sedans that had some of the worst acceleration imaginable. 90s, I agree, are much closer to current cars in capability.

Re:watch the program on 5th gear

[Computershack]

My gutless early 1980's European Econobox with a poxy 1.6 litre engine had a 0-60 time of 7.8 seconds which was only 1 second slower than the Ford Mustang which had an engine more than three times the size. Just sayin....

Re:watch the program on 5th gear

[Computershack]

Some people drove sports cars in the 70s and 80s, but most people drove heavy-ass sedans that had some of the worst acceleration imaginable. 90s, I agree, are much closer to current cars in capability.

Even 1980s US sports models such as the Mustang were quite poor. The 5L 1987 Mustang had a 0-60 time only 1 second faster than my 1.6L Escort.

Re: watch the program on 5th gear

[confused one]

By raw count, yes. By person miles, no. Speaking from personal experience... People just don't pay attention to bicycles.

Re:watch the program on 5th gear

[Smauler]

gentle acceleration because that is not only fuel-efficient

Citation needed.

Over a 50 mile stretch of road, the car accelerating at 1mph/mile will use more fuel than the car accelerating quickly up to 50mph. That is taken to the extreme, but it illustrates the point that more gentle acceleration does not necessarily mean better mpg - there must be a sweet spot in the middle somewhere, and I personally would guess it's a bit quicker than most would guess (my personally opinion is foot flat to the floor at low revs).

Re:watch the program on 5th gear

[lkcl]

you need to watch that program. have you watched the program yet? what did the program get across to you, and can you put it better than i can?

Re:watch the program on 5th gear

[mjwx]

people no longer drive sensibly: they are more aggressive with other drivers (not keeping a safe distance)

Is that why traffic deaths have consistently gone down since 20 or 30 years ago? - Killed_on_British_Roads.png

You'll find that's mainly due to crackdowns on the big killers on our roads, speed and drink driving.

The deaths on UK roads are almost 1/4 of that on US roads (2.75 vs 10.4 deaths per 100,000 pop). This is due to a combination of more stringent licensing, better training and more enforcement on speed and drink driving. Australia has similar enforcement on speed and drink driving but not the training and licensing so our deaths are only 1/2 that of the US (5.2 per 100,000 pop).

Re:watch the program on 5th gear

[james_shoemaker]

that's only true when you compare the mustang's 0-60 MPH reading to your escort's 0-60 KPH rating.

Re:watch the program on 5th gear

[toddestan]

Hey, the early 80's was a pretty dark time in terms of performance. It was normal for a new car with a V8 to only have something like 130 HP. Mostly due to primitive emission controls, and attempts to tune the car for maximum efficiency and not performance.

As a trend

[Justpin]

Since petrol went up to £1.36 a litre (thats $2.30) MPG has increased and actual fuel used has fallen partly due to people driving a whole load less. Back in 1999 driving to work in exactly the same town, took 35 minutes to get through one particular section. Today it takes 10 as there are fewer cars. However this is not in the best interests of the government! which is why the EU are mandating ET phone home systems in all cars from 2015 which allow you to monitor and track a car in motion acceleration and deceleration. The Labour government want to introduce a pay per mile system precisely because revenue from fuel taxes have fallen due to more efficient cars. Heh I've moved down from a 929cc missile down to a more sensible 650cc with 1/3 of the horse power..

Re:As a trend

[Anonymous Coward]

I call bullshit on the 'phone home system' that th EU mandates per 2015.

Re:As a trend

[Viol8]

>Heh I've moved down from a 929cc missile down to a more sensible 650cc with 1/3 of the horse power..

I assume you're talking about a motorbike?

Even a "sensible" 650cc bike will leave almost all cars apart from high end supercars for dead at the lights so on a day to day commute I doubt you'll notice much difference :o)

Re:As a trend

[Geeky]

The other thing that's changed is the way people drive on motorways. When I was first driving, back in the early 90s, you could sit on the motorway at 80mph (for those outside the UK, that's a little above the legal limit of 70) and be overtaken by a steady stream of ton-up drivers. The outside lane was a hazard and you'd need a huge gap to overtake and still have frustrated drivers getting right up your arse.

It still happens to an extent, but it does seem that the average speed has dropped. I see far fewer cars driving at 90 and up. OK, that's partly due to the increase in speed cameras, but I reckon fuel economy plays a part. There are more people seemingly content to sit below the limit, at about 60, and that was very much a rarity 20 years ago outside of the elderly cloth cap brigade.

Re:As a trend

[Justpin]

It's called eCall. It is mandated from October 2015 for new cars and vans. It can transmit GPS data and acceleration and deceleration and airbag deployment to the emergency services. http://www.europarl.europa.eu/... Everybody knows that there will be mission creep for this system, like a justification for the EU GPS competitor and that shortly afterwards there will be laws to retrofit them to current vehicles.

Re:As a trend

[Anonymous Coward]

I think he means: http://en.wikipedia.org/wiki/ECall

Which is an automated emergency call system in case of an accident.

Technically it does allow for the monitoring acceleration and deceleration, but cars tend to have this stuff already anyway, if only for the airbag controller.

Re:As a trend

[dyslexicbunny]

Is the plan to keep the fuel tax and introduce the per mile on top of it, I assume? What a pack of jackasses. They could just increase the fuel tax and problem solved...

Re:As a trend

[Anonymous Coward]

What Labour government? We have had a Con-Dem coalition in the UK since 2010, you must be posting from an alternate reality.

Re:As a trend

[Justpin]

I don't know, there is a massive amount of suspicion that these taxes per a mile are a red herring. With the alternative option of putting more taxes on fuel. When faced with two bad options people choose the least worst option, which was the option the government wanted in the first place, i.e. to raise fuel taxes. The problem of course is people countered this by driving a whole lot less and bought more efficient cars, so its all about the revenue protection.

Re:As a trend

[Justpin]

If you remember back before 2010 the Labour government were super keen on road pricing. They utterly denied it in 2000 before the election stating they had no plans for road pricing, about 3 days after the 2001 election they announced it as a future policy. They dropped it like a hot potato for the 2005 election yet again wanted to put it in place about 2 days after the 2005 elections. A labour policy making think tank announced something similar a couple weeks ago, whereby you were tracked and charged a different price at the pump for your fuel depending on what the mandatory black box installed in your vehicle said. Labour immediately distanced themselves from this policy. Which means they fully intend to implement this policy, come 2015 I have a horrible feeling they will get in on a landslide, as the Lib Dem vote is gone, the tory vote is split between UKIP meaning labour will be in power.

Re:As a trend

[Cederic]

Most people on the motorways I drive on are doing 80-90, except the cunts doing 70 in the middle lane with an empty lane to their left.

Re:As a trend

[dyslexicbunny]

I'm honestly not sure how one should fix it as electric cars become much greater in number. I'd hate to have a hybrid system where gas cars are fuel tax and electrics are per mile tax. But the solution I like is to have everyone pay a per mile tax to cover the roads and then gas cars pay the fuel tax as well with the revenues going to energy research.

Just like pints.

[Anonymous Coward]

There's a similar type of campaign that's been running for years to try and force pubs to serve a full pint, rather than including the head as part of it, either by serving no head (damn near impossible) or by using an oversized, lined glass so the head is on top of the fluid pint.

The problem with both issues is that while people may feel they're getting a better deal they're just going to end up paying more. If pubs have to change all their glassware and serve a little head for free then they'll just take that into account at the next price review, and likewise, if we force manufacturers to scrap their (government mandated, calibrated and already "accurate") rolling road systems in exchange for something far more expensive then we'll just see car prices go up.

We already know that advertised MPGs are not the real world figure, they're just for comparison between different vehicles. Personally I treat mine ("46mpg") as a perfect world figure, one full of frictionless spherical chickens, and if I get anywhere near it (usually ~43mpg) I know that both my car and my driving are at the efficient end of the scale.

Re:Just like pints.

[Anonymous Coward]

I'd pay a hell of a lot more for a pint if I got free head!

Re:Just like pints.

[TheRaven64]

The problem with the full pints campaign was that it introduced bigger glasses with a pint line a bit from the top, and people felt ripped off if the beer plus the head didn't go all of the way to the top of the glass. A number of surveys showed that people thought that they got more beer when they got a smaller glass that was completely full than a slightly larger one with a small gap at the top.

Re:Just like pints.

[newcastlejon]

There's already a rule about the size of the head but as usual it vaguely defined. As I remember it, "the head may not form a substantial part of the pint". This isn't helped by the fact that some drinks, e.g. lagers and ciders generally don't have much of a head at all, while others such as Guinness are expected to have a comparatively deep one.

The only way you're likely to get a landlord to top off your drink is if a) they're obviously taking the piss and b) you're not the only one at the bar. Having your punters see you fleece a customer is bad for business.

Re:Just like pints.

[ceoyoyo]

In Canada most places use lined glasses. The bartender is almost never going to actually look at the line, so you always get a bit extra. The point is that you know you're going to get a minimum amount of beer. Crappy bartender who pours a giant amount of head? No problem.

Fuel economy is the same thing. You can't tell if the inflated numbers for one car are more or less inflated than the numbers for another car. Not to mention you can't actually do any planning based on them.

Re:Just like pints.

[LinuxIsGarbage]

In Canada most places use lined glasses. The bartender is almost never going to actually look at the line, so you always get a bit extra. The point is that you know you're going to get a minimum amount of beer. Crappy bartender who pours a giant amount of head? No problem.

Fuel economy is the same thing. You can't tell if the inflated numbers for one car are more or less inflated than the numbers for another car. Not to mention you can't actually do any planning based on them.

At the microbrewery near me, the beer is sold in refillable 1.89L growlers. The proprietors always fill it as close to the top as possible, well in excess of 1.89L.

Which is why sometimes small engines ...

[Viol8]

.... arn't the best solution. If they're so underpowered or peaky - like a lot of the new generation coming along - then people will tend to drive with their foot flat to the floor a lot mroe often which hammers fuel consumption and doesn't do the mechanicals any favours. Whereas with a bigger engine this is less of the case and you can get equivalent mpg except with a less stressed engine that isn't going to blow a seal after 75K miles because of components being worked to their limit to make up for the idiotically small capacity.

Of course left to their own devices no manufacturer would be dumb enough to put a 1.0L engine in a 1.5 ton car but EU regs now require silly emissions targets being met in these unrealistics tests so the manufacturers have no choice.

Re:Which is why sometimes small engines ...

[Justpin]

1.0 litre engine in a 1.5 ton car... it happens! a lot of specified weights car manufactures use are dry not kerb weight. To get around the emissions standards for a while small engines (even 2 and 3 cylinders) were put into normal cars but they were given turbo chargers to cheat the regs. Sometimes it worked like the Daihatsu copen, 900kilos wet, with a 660cc engine which was turbo charged.

Re:Which is why sometimes small engines ...

[Sique]

It has not so much to do with emission standards, but with car taxes that are mostly coupled with engine displacement. A car with a smaller engine costs less in car related taxes, and thus buyers flock to the smaller engines, because the cars are cheaper to keep. The same is true for insurance, whose tariffs are often coupled with the power output, again making the smaller engine more cost efficient.

Re:Which is why sometimes small engines ...

[CeasedCaring]

In the UK, road tax has not been linked to displacement since March 2001 - it's all about emissions (CO2 in g/km) these days. See https://www.gov.uk/vehicle-tax...

Re:Which is why sometimes small engines ...

[KozmoStevnNaut]

A lot of the "new generation" of cars will have small turbocharged engines with direct injection and variable valve timing. Most will develop over 200Nm torque from below 2000rpm, not peaky at all. In fact, a lot of these cars with these engines are already on the road and have proven themselves both reliable and fuel efficient, as long as the owners actually drive them properly.

My car is decidedly old-tech in comparison, with a 2.2L naturally-aspirated 4-cylinder, rated at 8.8L/100km (27.7mpg). I average 9.0L/100km (26.1mpg) in mostly city and motorway driving, with ~160,000km on the odometer. I drive normally, stick to the speed limit or 5-10 over depending on the situation, and try to look ahead and anticipate traffic. It really isn't that hard to get very close to the ideal fuel consumption figures, you just have to relearn how to drive instead of going full-throttle/full-brake all the time.

Re:Which is why sometimes small engines ...

[Sique]

But the UK alone is a too small market to profundly influence the design decisions of major car manufacturers.

Re:Which is why sometimes small engines ...

[whoever57]

.... arn't the best solution. If they're so underpowered or peaky - like a lot of the new generation coming along - then people will tend to drive with their foot flat to the floor a lot mroe often which hammers fuel consumption and doesn't do the mechanicals any favours

In realitiy, it's much more complex than that. Large engines tend to be inefficient because they are driven with the throttles opened just a small amount -- google "pumping losses" for an explanation. Wide open throttle at low engine speeds (rpm) can be the most efficient mode, but, the if engine management system goes into open loop mode (which it will with rapid accelleration, wide open throttle, etc.), this will reduce efficiency.

Re:Which is why sometimes small engines ...

[Viol8]

You can't have the throttle fully open at low power with a petrol engine because you need to get the air - fuel ratio correct. So I'm not sure where you're getting your information from. Perhaps you're getting confused with how a diesel engine works.

Re:Which is why sometimes small engines ...

[whoever57]

You can't have the throttle fully open at low power with a petrol engine because you need to get the air - fuel ratio correct.

Please don't post about things that you obviously do not understand.

Of course the fuel-air ratio can be set appropriately -- it's just a matter of squirting enough fuel in. The way to limit power output is to use the gearing to keep the engine speed low (look at a power curve some time). Even at low engine speed, wide open throttle may produce more power than desired, so the you will have to close off the throttle somewhat. However, a small engine in the same car allows the throttle to be opened wider for the same power output than the throttle for a large engine, hence reducing pumping losses versus the large engine.

Like many designs, however, there is a tradeoff. The smaller engine may be less efficient at producing large amounts of power than the large engine because it may have to be operated at higher engine speed than the large engine, and high engine speeds are generally associated with lower efficiency. Thus a drving style that demands a large amount of power may use less fuel with a larger engine.
As I stated, it's complicated.

Re:Which is why sometimes small engines ...

[amorsen]

It really isn't that hard to get very close to the ideal fuel consumption figures, you just have to relearn how to drive instead of going full-throttle/full-brake all the time.

You are driving a car with non-faked figures. Of course you can get close to the official figures.

Relearning does not help you with most modern cars. They cannot physically achieve the numbers listed.

Re:Which is why sometimes small engines ...

[Smauler]

Car taxes linked to engine displacement are ludicrous. I've got a 1.8 litre normally aspirated 4 pot Japanese hatchback, that does under 15 seconds quarter mile stock.

Re:Which is why sometimes small engines ...

[lkcl]

Whereas with a bigger engine this is less of the case and you can get equivalent mpg

ah, i wrote a diesel truck simulator in 1993 for Pi Technology: there is actually much more to it than that. with a bigger engine with higher torque it is possible to have the vehicle drive more often in its peak torque range where it has either better acceleration or better fuel economy or both.

with a smaller engine the effect you mention - that people put their foot to the floor - means that the engine has to rev its nuts off and thus operates waaay outside of its efficiency band.

Re:Which is why sometimes small engines ...

[Viol8]

"Please don't post about things that you obviously do not understand. "

You obviously don't understand the irony of that comment.

" it's just a matter of squirting enough fuel in. The way to limit power output is to use the gearing to keep the engine speed low (look at a power curve some time)"

So have a wide open throttle and squirt more fuel in yet make the engine labour is your idea of saving fuel? Yeah, nice one, you should get a top engineers job any day now. All that happens in that scenario is the wasted extra fuel you're throwing into the cylinders gets turned into heat.

"However, a small engine in the same car allows the throttle to be opened wider for the same power output than the throttle for a large engine, hence reducing pumping losses versus the large engine"

The pumping losses you keep mentioning are minimal compared to the greater frictional losses in a larger engine. You ever wondered how much back pressure a turbo puts on the exhaust system? Its puts any losses in the throttle to shade.

Re:Which is why sometimes small engines ...

[whoever57]

So have a wide open throttle and squirt more fuel in yet make the engine labour is your idea of saving fuel?

Take a look at page 12 on this document and note where the most efficient operating point is. It's not quite at wide open throttle (and low engine speed), but it is close.

You ever wondered how much back pressure a turbo puts on the exhaust system? Its puts any losses in the throttle to shade.

I wonder if you are capable of reading. I did also write that a small engine may be less efficient than a larger engine if a large amount of power is demanded.

So, now I have a citation to support my point and what do you have? Just the irony that you keep suggesting that I don't know what I am talking about, while, in fact, it is you that is clueless.

Re:Which is why sometimes small engines ...

[OdinOdin_]

Heh, except for the matter that if they don't comply with whatever regulations come out they don't get approval.

While retrospective regulation on old cars is a political matter (pissed of public force to comply) the regulations affecting brand new cars is not. This is a matter for the auto industry to solve and the public don't care.

Retrospective regulations changes (that affect a significant number of the population) are rare events.

Plus there is that small matter of driving on the correct side of the road (that we do). So this does influence the which hand drive the car is.

Re:Which is why sometimes small engines ...

[Viol8]

"Take a look at page 12 on this document and note where the most efficient operating point is"

Any document that can't even get the location of the maximum torque correct isn't worth reading. It is NOT at max rpm as is indicated, that is normally where max power is located.

"I wonder if you are capable of reading. I did also write that a small engine may be less efficient than a larger engine if a large amount of power is demanded."

Yes, except this isn't the 1980s anymore - turbos operate over most of the engine rpm range and they allow a torque peak much lower down the range which means the turbo back pressure is occuring pretty much all the time.

"you keep suggesting that I don't know what I am talking about"

Seems to me all your knowledge comes from dodgy powerpoint presentations.

Re:Which is why sometimes small engines ...

[whoever57]

Any document that can't even get the location of the maximum torque correct isn't worth reading. It is NOT at max rpm as is indicated, that is normally where max power is located.

So now you resort to the claim that a paper by a professor at Cambridge University who lists "the internal combustion engine" as one of his research topics is incorrect about power and torque curves?

LOL!!!!!

I have provided a citation from a respected academic. You have provided nothing to support your claims.

Re:Which is why sometimes small engines ...

[Viol8]

I don't care whether he's a professor or not - he got that bit wrong. I suggest you compare the torque peak vs power peak of a number of petrol powered car engines if you don't believe me.

Over and out.

I dissagree ...

[Anonymous Coward]

I can reach the manufacturers figures if I follow the same speed profile as the test. That implies very slow accelerations, 0-40mph in 40 seconds, and low maximum speeds.
I can easily reach the 65mpg in a MW run if I limit the speed to 50mph (the average speed of the "official" extra urban test is just below 40mph).

The "official" test are useful to COMPARE cars and should not be taken as indicators of the real consumption. Every day consumption strongly depends firstly on the acceleration and secondly on the speed (as any cyclist would testify : ) ). The difference between "official" and real life values is smaller for low powered cars and larger for sporty ones. This is mainly due to the heavy foot syndrome, heavy on the accelerator and heavy on the break.

As a reference i'm including the description of the extra urban driving cycle,

The EUDC (Extra Urban Driving Cycle), introduced by ECE R101 in 1990, has been designed to represent more aggressive, high speed driving modes. The maximum speed of the EUDC cycle is 120 km/h; low-powered vehicles are limited to 90 km/h.

After a 20 s stop - if equipped with manual gearbox, in the 1st gear with clutch disengaged - the car slowly accelerates to 70 km/h in 41 s (manual: 5 s, 9 s, 8 s and 13 s in the 1st, 2nd, 3rd and 4th gears, with additional 3 Ãf-- 2 s for gear changes), cruises for 50 s (manual: in the 5th gear [sic]), decelerates to 50 km/h in 8 s (manual: 4 s in the 5th and 4 s in the 4th gear [sic]) and cruises for 69 s, then slowly accelerates to 70 km/h in 13 s .
At 201 s, the car cruises at 70 km/h for 50 s (manual: in the 5th gear), then slowly accelerates to 100 km/h in 35 s and cruises for 30 s (manual: in the 5th or 6th gear).
Finally, at 316 s the car slowly accelerates to 120 km/h in 20 s, cruises for 10 s, then slowly brakes to a full stop in 34 s (manual: in the 5th or 6th gear, lat 10 s with clutch disengaged), and idles for another 20 s (manual: in neutral).
Total duration is 400 s and theoretical distance is 6956 meters, with an average speed of 62.6 km/h (38.9 m/h).

Re:I dissagree ...

[Anonymous Coward]

Ok, that explains why I sometimes get better values. WTF are they doing driving in the 1st gear for 5(!!) seconds? 1s is the absolute max you should need. And 2s switching gears? Also, most of the time there is just no point in using the 4th gear at all.

> then slowly brakes to a full stop in 34 s (manual: in the 5th or 6th gear, lat 10 s with clutch disengaged)

What idiotic driving style is that? You wouldn't disengage the cludge but instead switch to a lower gear, so that the engine will not use any gas but instead will be kept going by the car's energy.
If people get 40% over that they must either be driving under very special circumstances or they are really incompetent at it and really, really need to take a course or otherwise get a clue.

Re:I dissagree ...

[Computershack]

I can exceed the values and not have to drive like a nun. I was lucky enough to do an economic driving course with a previous employer. Part of that was driving round a course around Birmingham and surrounding countryside. You were timed at the start of the course and at the end you repeated the run but not only had to improve economy but also do the route quicker and use fewer gear changes.

The biggest mistake and most fuel hungry is how people slow down. Engines use no fuel at all when you take your foot off the accelerator. You should be using engine braking approaching lights, junctions etc backing off earlier than driving to the point where you need to use the brakes to stop. It takes no longer to do the journey but all that distance you're slowing down using engine braking is free. As for the old wives tales about it wearing clutches out, the last car I sold had 165,000 miles on and was on the original clutch. The next mistake they do is not trying to time it approaching lights/junctions/roundabouts so you don't have to stop.

Re:I dissagree ...

[drinkypoo]

The biggest mistake and most fuel hungry is how people slow down. Engines use no fuel at all when you take your foot off the accelerator.

Only true for modern cars, or a tiny minority of vehicles otherwise. Otherwise they're still spending idle fuel.

Comparisons with electric range

[Anonymous Coward]

Does this also mean that the range comparisons with electric cars are likely to be less valid? They'd be undergoing the same test, but I'm assuming the differences in how they work would make them both have their ranges change under this apparently more accurate one.

It's just the way they're tested.

[Apotekaren]

The testing standards for the EU fuel consumption numbers are very strict and stringent and have never actually stated that you'll be able to reach these figures yourself. The cars are tested indoors, and are not in any way subject to real world conditions during this test. It's just a tool to standardize the way the cars are tested so as to give the consumer a clue when comparing different cars.
Because of course the car manufacturers are going to game the system by not only "cheating" with taping, over-inflated tires and such like mentioned in earlier posts, but also building cars in a way which makes them more optimal for this test.
The test itself includes both a urban-cycle and a non-urban cycle, which are then combined for an EU-average. The scores for all three measures are then stated by the dealership and as I said, they are mostly for comparing between cars and not estimating any real world consumption, because that would be almost impossible to do because of varying temperatures, road surfaces, drivers.... The list is long.

Re:It's just the way they're tested.

[Anonymous Coward]

In Australia, a similar issues.
As a 3rd world country, we have 3 petrol 'grades', so the first cheat is using super premium.
Off come the side mirrors, and test car can be taped up, and one presumes a miniature driver build like a anorexic jockey.
Can't remember is a spare tyre is required or not. Yeah, no honesty here. If you think that's bad, you should see our food labeling laws with false/deceptive country of origin.
I believe the test origin may be USA designed, as large heavy gas guzzlers do a lot better with a low stop/start cycle, say relative to a small, light Getz. Makes sense to rig the test to keep locally produced cars looking better than they are.

Might be true, but WhatCar can suck my arse

[Anonymous Coward]

It's probably true, but I wouldn't get a subscription.

I've worked for WhatCar, and they refuse to pay their contractors on time.
After threatening court action they finally paid.

I understand they did exactly the same to the previous developer, and they're doing exactly the same to the next one too.

All relatively the same

[petes_PoV]

economy figures that are on average 19% lower than the government figures

So long as ALL the official figures are equally inaccurate, the ranking still feeds into the choice of which cars are the more fuel-efficient and which are less so.

Therefore it makes little difference whether the figures are exactly what one would expect (though nobody is ever that naive) or out by a factor of two. You'd still expect that the little runabout with a 80 MPG "official" figure would be cheaper to keep topped up than an 30 MPG gas-guzzler.

As it is, few people take much notice of figures: official or not. It plays a small part in the overall choice (somewhere below what colour the car is) and is only part of the overall consideration of running costs + servicing costs.

Obvious explanation

[K. S. Kyosuke]

Apparently, there is an English proverb saying "if it moves, tax it". So it seems that the government has seen the cars move, and taxed them. 19%? That a tax-like number indeed!

Re:Obvious explanation

[newcastlejon]

Also inheritance tax, a.k.a. "when it stops moving, tax it".

rules

[kqc7011]

The manufacturers are following the rules that the governments set. It is not the manufacturers fault if they get different results then what the customers get. If you ran your car on the same loop the same way that the manufacturers do you would get right around the milage that they do. Of course they are gaming the system, but they are taking advantage of every little thing that they can. Me, I get quite a bit more MPG than listed on my motorcycle and a little less in the car. But in the winter the cars milage drops way below what is listed especially around town.

Re:rules

[cmdr_tofu]

When my car had a bad thermostat the mileage (and power) of the car dropped significantly. This was during the winter. After replacing the thermostat, efficiency and power were back up!

Re:rules

[Computershack]

They all do that. Its because it senses the temperature is cold so therefore runs in "cold start" mode which involves using a richer fuel mix, the modern equivalent of using choke on an engine with a carburettor.

Big News -- Not!

[Anna Merikin]

I am old enough to remember the "horsepower wars" of the '50s and 60s in the US. Inflation was rampant then as now.

So, what's new? It's not as if the governments know what they're doing, or their informational data is correct and unpoliticized....

Isn't this true in North America as well?

[gstoddart]

Isn't MPG based on an out-dated formula which everyone knows is wrong?

I also thought all the people who bought hybrids were annoyed to discover their actual mileage was nowhere near accurate, all because you're required by law to use the EPA formula which is essentially useless. I even seem to remember some people wanted to sue the car makers for using misleading numbers, but since they can only report the numbers one way, it's not something that can honestly report.

Sounds like it's time for someone to come up with a valid set of tests and numbers, because the ones we're using are clearly not based in reality.

The big question, is why have we been using an outdated formula which gives incorrect values when we know it? Who benefits from that? Is it lazy governments, or are is someone benefiting from this?

Re:Isn't this true in North America as well?

[Anonymous Coward]

Actually, the EPA updated the test in 2008 to make it more realistic. One side effect of this was that cars with undersized engine where hit with lower MPG figures due to the driver needing to open the throttle wider and rev higher which brought the engine outside it's efficient operating envelope. This gave Chevy and Ford; who tend to prefer larger displacement engines over higher rev'ing small engines; a better position in the mpg charts which is what actual drivers were already experiencing. I believe Toyota and others are working this into there newer models as now.

TASTE THE MEAT and the HEAT!

[Anonymous Coward]

i tell you what - huh, huh!

All I know is that the cars I want to drive

[mark_reh]

are not the ones that get the highest mileage ratings. Cars are not just transportation. Some people actually get pleasure out of driving, and some cars are definitely more pleasurable to drive than others. The ones that are most pleasurable, be they high end luxury sedans with all the comforts of your living room, or high performance sports car, get lousy fuel economy. That's the way it has always been and with the exception of electric sports cars, the way it's going to be for a long time to come.

Look at hybrid luxury sedans and SUVs. The advertising demonstrates that the hybrid stuff was added to improve performance and only slightly boosts fuel economy. People who buy those vehicles don't care about fuel economy because the cost of fuel is inconsequential to them. They care about performance and like the idea of being able to feel "green" as they drive their 2 ton SUV as if it were a Ferrari.

I believe that the human contribution to global warming is already tipped the balance so far that we won't recover from it. In another 200 years this planet is going to be a dessert. In the mean time, I want to get a Hummer. Not one of the tiny H3s that were made for girly-men who were worried about parking and fuel economy. I want one of the original beasts that could support rocket launchers. Then I want to convert it to burn coal, or better yet, lignite. I want to leave a sooty, greasy black trail everywhere I go that is visible from space. That will be my mark on history, my signature on this dying planet. THAT'S luxury driving!

Re:All I know is that the cars I want to drive

[Anonymous Coward]

"In another 200 years this planet is going to be a dessert"

You mean like, "To serve man?" or something.

Re:All I know is that the cars I want to drive

[mark_reh]

Oops!

Everyone already knew that

[Anonymous Coward]

It has been tested time and time again by infinite numbers of auto magazines and consumer protection groups. Everyone in the world knows that the manufacturer numbers are complete bullshit.

my anecdotal evidence differs

[cmdr_tofu]

Of course I'm not in the UK (even if I was wouldn't i be concerned with km/litre instead of m/g?) Anyhoo I drive a 2003 VW Jetta Wagon TDI (manual transmission) and according to fueleconomy.gov (http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=18793), the car gets 35 mpg city 45 mpg (avg 39) highway. From my experience it never gets less than 50mpg on highways (close to 60 driving between CT and NH), but now that I live in the city, with traffic jams, waiting several light changes in queues to make a turn, etc, I'm consistently stuck in the 40s.

This is different than fueleconomy's original rating of my car 42 city/50 (avg 45) hwy. http://www.fueleconomy.gov/feg...

Based on feedback from a small number drivers my car gets an average 48.3 mpg (with some reporting as high as 62mpg). So I have no clue why new EPA estimates are considered "more realistic" although they claim make their claims here: http://www.fueleconomy.gov/feg...
My suspicion is that it's just a way to make newer cars (which aren't as good in terms of economy), look better relative to old cars which are more affordable.

Re:my anecdotal evidence differs

[Anonymous Coward]

My Toyota Aygo claims 65mpg for 'motorway' driving. I used to regularly get that when I drove 30 odd miles a day on the motorway - at a steady 55mph! Was passed by everything.

So I think these figures are acheivable if you don't let your ego drive the car.

Re:my anecdotal evidence differs

[Computershack]

My Toyota Aygo claims 65mpg for 'motorway' driving. I used to regularly get that when I drove 30 odd miles a day on the motorway - at a steady 55mph! Was passed by everything.

So I think these figures are acheivable if you don't let your ego drive the car.

That's terrible. I get that out of my MK4 Ford Mondeo doing 70MPH on a motorway. The most I've had is 70MPG.

Effect on American Market??

[Anonymous Coward]

One of the problems this is creating is that we have do good politicians asking why American Market Cars aren't getting the fuel efficiency of European Cars... Well, they aren't the same measurement, the EPA does the testing the USA while several independent labs do the tests in Europe. Since the labs are paid by the Car companies they compete with each other to find new creative ways to stretch the MPG of cars while still certifying the cars. It's a miracle some labs don't just out right lie about the cars fuel economy.

It would be nice if the EPA and European Union could create a single standard for gas mileage...

True MPG does not matter; true relative does

[WindBourne]

Seriously, what matters is the relative MPG. The fact is, that the owners driving conditions will change the true MPG.
BUT, knowing that something is rated at say 30 MPG vs. 40 MPG using the same car that I would buy (i.e. nothing rigged by the makers), will make a difference.

Of course, a number of us are moving from MPG to MPC (miles per charge).

Duh!

[Anonymous Coward]

Duh!

Duh!

[Anonymous Coward]

It's been known for years that the mpg tests are done by midgets weighing 40 kilograms, mirrors taken off, seams of the doors taped, 5 liters of petrol in the tank, very slow acceleration etc. This can hardly be called news.

Which fool deletes my comments?

[Anonymous Coward]

yes you!

In further news

[CharlieG]

The sky is blue, ice is cold, and politicians lie

US city figures too

[Lawrence_Bird]

Probably unknown to many people is that US city epa estimates include driving on the highway.

Hugely dependend on manufacturer

[Anonymous Coward]

I'm a field technician and drive a lot (about 50k kilometers a year).
This also means I regularly get a new car, because the company replaces my car at about 100k to 150k kilometers.
I've driven a number of cars (always European brands), all diesel of course, and checked the manufacturers mileage - some are extremely misleading, some are spot on.

Currently, I'm driving a Renault - the manufacturer claims a mixed consumption of 3.5 l / 100 km which is just ridiculous. Even with careful driving, I can't get it below 5 l, usually it is 5.5 l to 6 l.
Previously I had a Volkswagen with very similar specs - claimed was 4.5 l / 100 km mixed, with a minimum of 4.2 l, which I managed to beat several times with a minimum of 3.9 l actual consumption over the range of a full tank. Usually I still needed 5 l because I don't really like to drive slowly :)

So, to me, it is obvious, that some cheat more than others - and some might actually not be cheating at all.

I realize that this is anecdotal, but over the last 5 cars I certainly got a consistent impression. My numbers are not derived from the on board computer, I calculated them based on the refills at gas stations.

UK thing?

[jon3k]

The last two cars I've owned (BMW and now Audi) have hit the manufacturer's numbers exactly. I've been shocked, frankly, by how accurate the estimates were.

Re:UK thing?

[steve_parkes]

Well I'm in the UK and my Merc doesn't come near to the stated figures unless I'm breaking the speed limit on the motorway so it's not a German car thing that's for sure :)

Engineering

[Etherwalk]

That's all true, but manufacturers go to great lengths to inflate the figure.

I do wonder how someone so odiously dishonest as to participate in the practices you describe could ever become an engineer for a successful international brand.

Then, as someone who has been self-employed since 2003 and who has seen such a huge change in the way clients behave over the past decade, I wonder whether odious dishonesty today is a job requirement.

You have it backwards. They move toward dishonesty because they are working in a culture that (without calling it dishonesty) does dishonest things. For example, recently there was a memo in the News showing that GM prohibited engineers from using certain words like "defect" so that those words wouldn't show up in future lawsuits. This process is insidious--by itself it doesn't *have* to be dishonest, but it distorts the truth enough to make people a little more comfortable with distorting the truth.

Re:Engineering

[sjames]

Part of the problem is the complete and utter failure to enforce any sort of truth in advertising. If the liar gets away with it a few times, the rest have to either start lying or start dying due to loss of sales.

The same crap happened in broadband. Everyone promises unlimited use at a bazillion Mbps. Nobody will actually deliver that to you. As a result, even where there is more than one choice, you can't do a proper comparison of price vs. what is actually provided.

Of course, God forbid that the customers might exaggerate about how much they'll be paying and how reliably!

Driving faster help my MPG ... YMMV

[perpenso]

Probably also driving too fast... European emission standards require testing at 90km/h, while the max speed in most EU countries is 120 or 130km/h

I'm in the U.S. and my car is rated 22mph city 29 mph highway. The city rating is dead on. The highway rating is off, I actually get 34 mph rather than the stated 29. My typical highway is designated 65 mph and when traffic is light it is practical to do 75 mph. At 75 mph I get 34. The rating of 29 may be based on obsolete 1970's 55 mph standards.

Maybe 55 was optimal with 1970's auto technology but it doesn't seem so today, at least for me. And of course YMMV is quite appropriate here.

Re:Driving faster help my MPG ... YMMV

[guruevi]

I noticed something similar with US cars. Apparently the gear ratios are set to get the optimal MPG under testing conditions (50 USMPH without AC) which makes the transmission shift down (and thus higher rpm) when you're going 55 with your AC and other accessories on, then switching gears/going into overdrive between 60 and 70mph.

Re:Driving faster help my MPG ... YMMV

[perpenso]

FWIW my car has a six speed manual transmission. 6th is not practical until 60+, AC on or not.

Re:Driving faster help my MPG ... YMMV

[parkinglot777]

Maybe 55 was optimal with 1970's auto technology but it doesn't seem so today, at least for me.

You should also realize that there are still many highways that limit the speed at 55mph (I still see 50mph in certain places that the highway turns into a town/city road). I believe it is much safer for the auto manufacturer to officiate the mph to a lower number, or it would likely become a false advertisement (in a bad way for consumer).

My car gets better mileage...

[mspohr]

My car is rated 27/38 by US EPA.
Over the first 36,000 miles, I have averaged 42 MPG (two drivers).
I'm obviously happy with this result.

This Has ALWAYS Been True

[Toad-san]

One of the biggest "Doh!" moments lately. I can't believe some consider this news.

Look at test profiles, but works for me

[Anonymous Coward]

The EPA test profiles can be found here:
http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

They use fairly mild acceleration, no A/C, highway max of 60 mph.

Unrealistic? Depends on your driving and your route. I have a new 2014 sedan listed at 25 city/ 36 highway. After filling up the car in another state Sat., I drove 50 miles back home on low traffic 2-lane roads, going 60 mph (55 speed limit), passing through a few small towns (including stops), temp in low 80's so A/C on. Result: 36.0 MPG. Now if I had been going 75, into a headwind, with several people in the car, etc., obviously it would have been lower, but that sort of thing should be obvious to anyone with even half a brain.

Didn't read article - text too GREY

[Anonymous Coward]

Are you sick of this ubiquitous 'grey text' bullshit yet? Isn't there a single web designer on the planet who can think for themselves, and just use BLACK text? What a bunch of bandwagon-jumping assholes 'designers' are...

Yes, and

[justthinkit]

Yes, and still paying out. Every year we fill out a form, drive to our local dealer so they can read how many miles we drove that year and then get a proportional check for our Kia Soul. :-)

Real-world conditions

[sushant023]

Under-inflated tires, lousy fuel, ignored maintenance, rapid acceleration, more than one occupant / actual cargo, stop-and-go traffic, air pollution, air pressure variation, air temperature variation, elevation variation...

And these are just a few of the things that would cause your "official" MPG figures to deviate from observations.

This is true, but the official tests are in very ideal conditions. Not possible to get even close to them.