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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."
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.
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.
Isn't the more important thing that the all the cars figures are comparable.
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?'
--- Often in error; never in doubt!
Usually I think of lower figures as better. Especially in the UK with litres / 100km.
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.
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.
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..
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.
Except that the Prius costs more energy to make than many vehicles with a higher fuel consumption.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
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.
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.
.... 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.
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.
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.
She: Hey, are you a traitor? Me: No, I'm atheist.
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.
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.
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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!
Ezekiel 23:20
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.
Passionately Indifferent
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?
Lost at C:>. Found at C.
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!
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.
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.
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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.
If you ignore the lithium ion battery pack? yes.
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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).
I prefer the "u" in honour as it seems to be missing these days.
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.
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.
The Prius battery is NiMH. Some other hybrids might use Li-ion.
Ooh, moderator points! Five more idjits go to Minus One Hell!
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Probably unknown to many people is that US city epa estimates include driving on the highway.
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.
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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.
I only please one person per day. Today is not your day. Tomorrow isn't looking good either. - Scott Adams
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.
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.
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.
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.
I don't read your sig. Why are you reading mine?
One of the biggest "Doh!" moments lately. I can't believe some consider this news.
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...
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.
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If a bunch of MBAs say so it must be true!
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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.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
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. :-)
I come here for the love
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.
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.