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Fuel Efficiency Numbers Overstate MPG More For Cars With Small Engines
whoever57 writes: All official numbers for fuel economy in the EU typically overstate the miles-per-gallon figure that drivers can expect to achieve in typical driving. A recent study confirmed this once again. However, what the study also found was that MPG figures are more unrealistic for cars with smaller engines than for cars with larger engines. Actual MPG figures achieved based on typical drives for cars with small engines could be as much as 36% under the official number, while those cars with 3-liter engines would typically achieve 15% less than the official figure.
These discrepancies need to be accounted for if we're going to be serious about regulating fuel efficiency. But then, we should be using gallons-per-mile instead of miles-per-gallon, too.
"But then, we should be using gallons-per-mile instead of miles-per-gallon, too".
No. You should be using litres per kilometer. Especially so when talking about the EU.
In marketing, bigger numbers are usually better, except for the price. This is why we use MPG and why they put big numbers on the speedometer even though that 4 Cylinder would never make it to 120 MPH.
Windows 7 becomes Windows 8 becomes Windows 8.1. Boeing 727, 737, 747, 757, 767, 777, 787.... Airbus 320, 321, 330, 340, 350, 380... Ford F-150, F-250, F-350. Each increase is supposed to represent the product getting bigger and better.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
I find that pretty much all cars are capable of reaching the MPG ratings on their windows stickers... the problem is, you have to drive under certain circumstances to reach those... small engines are very economical when driven properly (slow acceleration, maintaining the speed limit for highway or city driving, etc.) but can come in way under their rating when the driver accelerates hard constantly and drives 10-20 MPH over the posted speed limit. I drive a Focus ST, and during extensive MPG testing, I've seen this first hand. A turbo 2.0L engine, capable of much speed and acceleration, and I usually maintain about a 24-25 MPG average, which is the rating for all city driving, but I don't drive it gently most of the time. When I did test out how much I could get, it hit the numbers exactly, hitting 32 MPG on all highway driving, at 65 MPH / 55 MPH. I think the problem is, people buy a Prius and expect it to hit those lofty numbers no matter how they drive, then they floor it from every stop and drive 90 MPH down the highway, wondering why their MPG are so low.
All official numbers for fuel economy in the EU typically overstate the miles-per-gallon
And here I thought it was only NASA that had metric and imperial units mixed up. Obviously the number is going to be higher. There are 3.785412 liters per gallon.
The numbers are not overstated based on the test criteria. It is the test criteria that does not cover the real world operating conditions. Change the test requirements, and you'll change the results and therefore the rating.
If you try to push a small engine to drive like a larger one, you'll be accelerating harder, therefore using more fuel than under normal acceleration.
In similar manner, some years ago, I had a Grand Cherokee that my wife couldn't get more than 11mpg out of, while I could do 17mpg.
We have different driving styles. She is a leadfoot, while I drive like I have an uncooked egg between my foot and the gas pedal.
Perhaps this article might better be titled "Want better gas mileage? Don't drive like a gashole."
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
"But then, we should be using gallons-per-mile instead of miles-per-gallon, too".
Depends on your use case. I generally want to know how far I can get on a certain amount of fuel, therefore miles per gallon are better for me. (Actually, miles per litre would be ideal for me as a UK driver despite being a horrible unit, as we measure road distances in miles and sell fuel in litres.) If on the other hand you want to know how much fuel it will take you to travel a certain distance then litres per km (or the weird unit that appears to have become standard in the EU, litres per 100km) would be better.
To say one or the other is always better is wrong.
Well it was interesting until they started talking about everything being more efficient at 55 mph. At that point, I was ready to give the author a boot party. Do not EVEN start that sh*t again.
Proverbs 21:19
Practically every card on the road today has a feature which calculates MPG (or L/100KM) historically. Just add a data field in the car's computer that keeps the historical number, even if the one on the dash is reset, and download it from a % of cars at their annual inspection. Won't help for new models, but will, over a couple of years, develop a very robust data set saying "the Ford Model XYZ tested at X MPG, but real world MPG are Y." Not flawless, naturally, since a different set of drivers for each vehicle will mean that the results aren't entirely because of the car (take the drivers of Buicks, and put them in Porsches, and they'll probably get better MPG than the average Porsche driver will), but will give a good indication to a person buying the Porsche (who's probably in the "Porsche driver" bucket anyway) of what he/she can actually expect.
Hell, they would do it downhill if they could getaway with it.
As for 'more for small cars', if you remove 30 lbs from a 6,000 lb vehicle, that is 0.5%, but if you do the same for a 3,000 lb vehicle, it is 1.0%. So yeah, optimization works better for a smaller car.
excitingthingstodo.blogspot.com
Even though they are part of the EU, the UK still uses many imperial units such as MPG instead of l/100 km.
And frankly, the rated MPG is just a tool to compare different vehicles under standard conditions, it isn't an estimate of your actual, real-world use.
In fact, with my last 2 cars I had better than the rated fuel efficiency, because I don't drive like an idiot.
From the article: "Motorists are usually advised that smaller cars can travel more miles per gallon (mpg) than those with larger engines" This is false on many levels:
1. A car with a smaller engine will have better MPG than a car with a bigger engine.
2. A smaller car doesn't always have better MPG than a bigger car, the weight of the car is the biggest factor.
For example, the mini is a small car, but the MPG is much lower than you would expect for a small car, because it is so heavy.
Probably most of it comes down to driving style. People who are used to older cars with bigger engines will probably think a new model with a small engine is gutless and will floor the accelerator to make it go faster. Anecdotally, I drive a 2005 Civic Hybrid, which was originally rated for ~46 MPG with the "less realistic" measure EPA used back then. I've driven it 170k miles now and that is in fact its lifetime average - it has two trip odometers and I never reset one of them. However back when these were still pretty new I read reports of people who complained about getting only ~33 MPG out of an identical car. The only reasonable explanation is that they were flooring it between stoplights and generally ignoring the instantaneous and cumulative MPG display the car gives you.
Basically people are impatient and don't know how to drive efficiently. It took me a few months to really get into the groove with mine and I still have to make sure I've got plenty of room to pass on the highway, but it's certainly doable.
Hail Eris, full of mischief...
E pluribus sanguinem
Most cars are only carrying the driver, and doing speeds of less than 120 kilometres per hour.
In the rest of the world you don't need a multiton SUV for those uses.
A 1 litre normally aspirated 4 cylinder should be enough.
You can also get more MPG by using proper size gallons. (4.54 litres)
A one mile trip from a cold start would be a useful number for many people. Start car, drive kids one mile and back home, turn off car and six hours later one half mile for groceries and home. This type of driving can get some awful mileage results and for some people this is 90% or better of the use of a vehicle. I think the numbers from such a test would be a real shock for many drivers. And then there are those of us who live in areas where the car AC will be running twelve months a year. Mileage with a heavy AC load will also be quite different than expected.
would it not be better to simplify a volume divided by a length to an area. Gallons/mile is best represented in represented in hectates or furlongs^2.
Some drink at the fountain of knowledge. Others just gargle.
5+ liters or go home!
We *should* be using L/100km, like everyone else.
And taxing fuel at a higher rate instead of this CAFE silliness. But that's never going to happen because if we know one thing about economics in America it's that all taxes are always bad.
0 1 - just my two bits
1 US gallon / mile = 0.00364583333 sq inches
Some drink at the fountain of knowledge. Others just gargle.
Firstly, I use petrol.
I now avoid all supermarket fuel, since the last time I bought a tank full (not saying where) that drove like all the staff had pissed into it and I really thought the poor car was going to give up and break down on it. Until then, mileage per gallon seemed to vary from tank full to tank full, suggesting to me that quality varies, so now I avoid the stuff altogether.
What surprised me recently, though, was that when I filled my 2003 Honda Jazz at a particular station on the way home from a weekend visit to a friend, and started driving off after resetting the trip counter as usual, the mpg indicator immediately started showing a far higher number than usual. So, I tried driving for economy for the rest of the 20 or so miles journey home which has a variety of level and hills, and when I got home it had done 64.5 miles per imperial gallon. What the hell was going on? I usually get more like 47 or 48 mpg.
I can only assume that the tanker driver accidentally dumped the "good stuff" super unleaded into the ordinary unleaded tank, because last weekend I purposely bought the more expensive super unleaded (again I'm not saying which brand) and achieved exactly the same mpg on the way home. If this is consistent, it's actually worth buying the more expensive grade of fuel to get the extra mpg.
My friend who has a 2005 Jazz is going to try the same experiment with the same fuel from the same filling station to do the same journey. We'll see!
My very limited experiment of three tanks of fuel also suggests that you get more mpg with the fuel from one brand than from others. So, I know what I'm buying in future.
The study is by Emission Analytics, and here is the original link (as opposed to TFA from The Telegraph).
Note some misleading elements from TFA: they show only the three smaller classes for UK cars, seemingly indicating that small cars are the worst gas guzzlers, whereas cars with higher engine sizes are actually much worse according to the original study (see the graph). So the lesson is: still buy a small car, just not a very small one for best fuel efficiency.
Another interesting bit that is not in TFA is that the data for US cars is different: there, cars between 1 and 3 liters in volume (I assume this is the large majority of the car pool) have less than half the mileage. Also, the smallest US cars are actually the most efficient of any class, even though their efficiency is below UK average.
Victims of 9/11: <3000. Traffic in the US: >30,000/y
1. Carmarketers like good gas mileage figures; they're good for sales.
2. The specifications for the test are gamed to provide a bigger benefit for underpowered cars which tend to get better mileage anyway. The test include acceleration at a rate *that depends on the car's power* (percent of full-throttle). which has the big-engine (more powerful) cars zipping around the virtual course at higher speeds.
Remember, lobbyists write or co-write most of our laws and regulations.
Because it's a standardized test. That it doesn't represent real life is not a surprise. That it seems to favor specific design features over others should not be a surprise and doesn't invalidate the results. I repeat, this is a standardized test.
Manufacturers spend big bucks to get their designs rated and certified though the EPA's mandated testing. CAFE standards are mandated for the manufacturers whole fleet. I'm sure they spend more money on the higher volume units to reduce fuel consumption and raise MPG for the fleet. This means they will more strictly control how the car is driven though the testing course, the test conditions will be optimized more fully, and mileage will be better. I also believe that people who drive smaller engined cars tend to be more aggressive in terms of throttle settings and other engine load (AC blowers, vehicle loading, radios etc) than the standard test cycles require, thus they don't get the stated mileage. Also, the mandated test conditions are quite specific and deviations from actual test conditions can lead to significant changes in mileage.
So this mileage difference is not really a problem to worry about. We simply have to keep standardized testing and the differences between the test results and real life are not something we can fix..
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Top Gear had an interesting experiment where they raced a Prius against a BMW M3. But what they did was have the Prius go all out and the M3 just paced it. Then they measured the actual gas consumed and found that the BMW had better mileage under those circumstances.
Some time ago I had a big old V8 car and I could pretty much halve my mileage simply by being only somewhat more aggressive. City driving would also send that car's mileage into a tailspin. The rated mileage was around 23/18Mpg but I would say that with gentle highway driving I could do 23 but with typical city driving it might have been below 12.
So what I would like to see for a metric would be something similar to the Top Gear scenario; basically they would drive the car around a test track at three(light, normal, and lead foot) given sets of reasonable accelerations, braking, speeds, etc and then tell us the consumption rate. Then we could compare apples to apples when buying cars.
In my '06 VW TDI I was pulling 42+mpg (trip odometer and gas receipts) consistently with the cruise set at 65 and 79mph (highway/interstate) with little in-town travel. And I'm the kind of guy that, "drives it like he stole it". Even now with my new commute being ~15 mintues of stop-and-go traffic and ~10 minutes of blasting around country corners and hard accel/braking I still manage 34-36 mpg.
The '06 VW Golf TDI was rated at 31 city, 40 highway, 34 combined:
http://www.fueleconomy.gov/feg...
One day I bumped into a hyper-miler with a '06 VW Jetta TDI (non-hatchback version of the Golf) at the gas station in town that sells Diesel. He ran low resistance tires, swapped out 5th gear for the 6th gear out of the performance tranny, chipped the computer, and drove slow enough to be annoying. With all that he was pushing 60mpg.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
(that being the USofA) is to worry about how far we can go on a tank of fuel. This is a throwback to the days when trips of any significant distance could easily leave you stranded between fueling stations (which used to be as much as hundreds of miles apart)
In that case, knowing distance per unit of fuel is more important than fuel per unit of distance.
In Europe, where distances are SIGNIFCANTLY shorter it is much more interesting to worry about the cost of the trip, especially when public transport options are close competitors in price. In this case the unit of fuel per unit of distance makes a much easier comparison.
I measure my "fuel economy" in miles per KWh these days.
Yeah, yeah, one data and all that.
My 2010 Hyundai Elantra claims it will get 29/40. The first time I took it on an extended (highway) trip, I got exactly their 40 mpg figure (actually a fraction above).
As to local driving, I filled up yesterday and the calculation gave me 32.22 mpg though I don't drive what one would consider true city driving such as in New York or LA, more a hybrid of stopping and starting with some distances in between. That is comparable to my usual number with has been as high as 35 in this hybrid city driving.
Obviously winter driving kills your mpg but every car I've driven for the past several decades have all been these types and I have consistently gotten above what the manufacturer says. And no, I'm not doing hyper driving or anything like that. Just common sense driving such as not flooring it to the red light then slamming on the brakes, heavy acceleration off the line and related driving maneuvers.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
Inches is the unit we measure pressure in.
None of this should be news to anyone remotely familiar with physics. Number of cylinders and engine capacity generally translates into a torque value, which is power to move a given weight over a given distance at a given rate of travel. A small engine car will show great fuel efficiency - when it is not moving something that weighs as much as a car and, say, four occupants. It takes more work (read: fuel consumption) for a small engine to move 2 tons 1 mile than the same weight over the same distance. A car with a larger engine will work "less" to do the same amount of work because it produces more power with the same amount of fuel. Where a small engine shines is slow-moving traffic in a city environment, where the engine idles more than it moves from point to point.
But then again, if you are really moving that slow, why not take a bike/train/bus/walk?
Let's see MPG or 1/MPG. Very important to invert it.
This is what happens when uneducated, uninformed Peter-Principle bureaucrats dictate fuel efficiency standards without checking with real engineers to find out if it's even possible.
In California the governor IS mentally disabled, does that count? He wants to spend Billions of dollars on a train that nobody will use, when that kind of money could be spent widening and adding roads, which would demonstrably lower the over all use of fuel in the state.
TFA is about British/European efficiency tests. US gas mileage numbers are significantly more accurate because they measure higher acceleration and average speeds. The EPA mileage estimates for any given car are generally significantly lower than EU tests on the same car.
As for small engines vs large: mileage tests are run with the AC off.
AC usage uses a much larger fraction of a small car's power at cruise, so mileage decreases faster than for large cars.
I had a 10 year old for Explorer, 5.0L V6, All wheel drive, 114k miles and I used it like a truck, lots of hauling. etc. In a mirage of advertising, I started to look at a crossover to replace the vehicle as my needs have changed. I ended up with a KIA Sportage with a towing package so I could still haul smalls loads but keep it as a more family vehicle but still get some benefits of a SUV. The Sportage has a 4 cylinder engine and a listed EPA Hwy MPG of 29 I think. Which is much better than the 15 - 18 I would get on my Explorer. After having the Sportage for a month or two the fuel economy sucked, city driving mostly, stop and go traffic for miles and miles and was getting 17 - 20 MPG. When I finally made my first long drive I got 27 - 29 MPG in the Eco mode. After a few more months I found a key to getting better MPG, I have to absolutely baby this vehicle, keep it in Eco mode and watch the indicator and keep acceleration slow and easy and highway speed to no more than 65 - 70 for the best economy. Now I am getting 24 city driving and 32 on the highway, which is still way below what my expectations regardless of the stated EPA estimates.
But then, we should be using gallons-per-mile instead of miles-per-gallon, too.
A car that does 50MPG is twice as efficient as one that does 25MPG. What's so hard about comparing numbers in MPG? It sounds like me like someone's got a case of the "technically correct"s.
systemd is Roko's Basilisk.
My 2011 Jetta TDI was rated at 42 MPG highway and I regularly got 48-52. My 2014 Honda Accord is rated at 36 highway and I regularly get 38-40.
For many of us in the USA, you're assumption about what we care about is bullshit wrong.
I live in Portland, Oregon. If I'm going north or south, I'm sometimes interested in mpg, but it isn't a big thing. Never very far from an Interstate highway in those directions.
But if I'm going northeast or southwest, mpg is critical, because there are too many back roads in the Washington and Oregon outback where running out of gas would put one in serious danger, and not be just a bit of an inconvenience. Having to hike 50 miles to the nearest gas station in the summer heat with no water or shade to be found is something to avoid.
This is not unique to Oregon. There are a lot of places throughout the USA where people often drive into what passes these days for wilderness, where if you don't estimate how many miles you've got left in the tank, you could end up in an unhealthy or even deadly experience.
MPG is the sensible measure to use in North America. Perhaps someday that will become kpl, but it will never make sense to use gallons per mile or kilometers per liter.
Now fuel for construction equipment that might travel all of 10 miles in an 8 hour shift needs to be measured in gallons per hour, but that's an entirely different thing.
Will
I have a 2010 Honda Fit with the manual transmission and a 1.5l four-banger. In my real-world driving, I get about 32-36 MPG in city driving, and 38-42 MPG on the highway. As it turns out, that's quite a bit better than the EPA numbers: 27 city/33 highway. I try to drive efficiently at least, but I wouldn't consider myself to be a hypermiler, either. I can't help but think that the EPA numbers assume idiotic driving with jackrabbit starts and racing to red lights. And now they're claiming that the estimates overstate things?
Oh, no! You have walked into the slavering fangs of a lurking grue!
Now lets try the same using the metric system:
1 litre / kilometre = 1 sq millimetre
That is another win for the metric system in my book.
I know in the US road maintenance is payed for with gasoline taxes from the various entities which collect an excise tax on gasoline. These taxes have taken a hit with the rise of more fuel efficient and electric/hybrid cars. The excise tax on gasoline per gallon no longer taxes the effective goal of the tax, which is to tax the miles driven, not the gas consumed. But for various reasons the excise tax has to be collected on gallons pumped, not miles driven. Since miles driven is what wears the roads down, not gallons of gasoline consumed, electric cars basically drive "for free" on the roads, hybrid cars get a huge discount, and everyone else pays most of the taxes that actually fix the highways. Since no one wants to pay more at the pump or install something that allows you to be taxed on miles driven, the broken system remains.
I know in Europe the fuel taxes are more severe, and also not exclusively related to road maintenance, but I imagine the taxation regime is similar and also broken.
Anyway, point is the overestimation might be related to bureaucrats' desire to collect more taxes from a broken taxation system, rather than actually reform the fuel tax to be more effective and fair.
As far as I can tell the central thesis in the "mpg vs. gpm" link is basically: "An increase of 5 mpg on a vehicle with base efficiency of 10 mpg makes a much larger difference in total fuel consumption than an increase in 5 mpg on a vehicle with base efficiency of 30 mpg--using the reciprocal mpg form masks this difference."
It took me awhile to understand this argument because I (like most people, I imagine) see the first case as a 50% increase in efficiency while the second case is a 17% (5/30 == 1/6th) increase in efficiency--so of course the first case leads to a much larger reduction in fuel efficiency.
Real driving pushes small engine harder than the ideally pristine MPG test, making the actual number much higher, closer to the MPG they quote on the powerful luxury cars.
For a luxury engine, on the other hand, real driving does not push it close to its max power, making actual MPG closer to that of spec quote.
My Mazda CX5 was quoted with 24/30 MPG, while in reality I get only 21 while driving mostly highway. I might get a different car if not for this fake quote.
I get this is a generalization, but cars with huge factory turbochargers tend to be rated much *lower* than they get in reality.
My car is a 2012 Lancer Evolution X GSR with a turbocharged 2.0 inline 4 using a huge factory turbocharger that produces 300 horsepower and 300ft/lbs of torque at a low 3000rpm. The same engine is sold overseas with an even larger turbocharger producing 440 horsepower and 418ft/lbs of torque at 3100rpm.
My car is rated 17 city 23 highway yet I can easily get 25mpg in the city and 32mpg on the highway. Remember this car has a full-time four wheel drive system that cannot be turned off and the engine produces a whopping 150 horsepower per liter. (compared to about 74hp per liter for American pushrod V8's)
The factory tune runs rich under boost which means it wastes more fuel than usual when boosting. But if you stay out of boost the fuel economy is quite a bit better. It's almost as if the test for MPG assumes you will be an idiot and driving around in boost all the time.
Now the bad reputation Ford Ecoboost has for real-world fuel efficiency, is real. Their turbo 2.0 only produces 250 horsepower and 270ft/lbs of torque and it's direct injected which means it can run leaner under boost saving fuel. Even then the turbocharger is so much smaller than the Lancer Evolution that it's too easy to build boost with gentle throttle inputs. That means you can't really drive it out of boost because any bump of the pedal will instantly spool up the fuel-wasting turbocharger. But my bigger turbo doesn't get going until around 3000rpm so if I short shift I can still get decently on the throttle before spinning the turbo which means I can drive way beyond the EPA MPG rating with ease.
But thanks to Ford and their super small turbochargers people in general are starting to believe that turbochargers are bad for mileage in general...... In reality it's only bad to use tiny tincy little turbochargers like the Americans are doing.
For reference Mitsubishi in 1993 sold a production 2.0 I4 making 250 horsepower. Ford Focus ST in 2013 was released with a turbo 2.0 I4 making 250 horsepower. (Mitsubishi beat them to the punch by over 20 years). In 1995 Mitsubishi raised that to 270 horsepower which was more than the 1999 Mustang GT's 260hp V8. (In 1993 the Mustang 5.0 made 225 horsepower).
Americans are just really far behind and their turbo cars are making everyone in the industry believe that turbocharging does *not* increase mileage. Yet my *23* miles per gallon import car with four wheel drive can easily hit 31mpg. 35mpg in perfect conditions at slow speed. It's all a wash.
Here's one easy solution to your problem - when the tank hits 1/3 full, stop at the next gas station. There are VERY VERY few places in the US where the direct route from A to Z is 100 miles long and doesn't pass a single gas station.
Maybe the people complaining about the numbers should try driving more efficiently?
I researched my new car purchase extensively. I normally do not buy brand new cars but with the driving habits I currently have (100 miles a day for work) buying a used car didn't actually pan out with my 30,000 miles a year figures. A new car with good gas mileage that could fit everyone in my new family (just had 2 kids in the last 3 years and the 2 door Honda didn't cut it anymore) was just what I needed.
I researched the sedan market and was drawn to the 2014 Honda Accord, Ford Fusion, Nissan Altima, Chevy Cruize, and Toyota Camry. I needed to pull a small trailer with a motorcycle and 4 wheeler from time to time so the Hybrid models like the Prius were out. I went to the dealer and test drove each and every car and all the stickers boasted between 33 and 38 highway MPG (which is 90% of my driving). I'm a Honda fan at heart but the Accord just didn't feel very driver friendly and I really didn't like how it drove as much as previous models I had looked at. When I sat in the Ford Fusion I knew this car was special. It drove like a freaking dream, felt very comfortable, was super quiet, and just had loads of power for such a small plant (the 1.5L Ecoboost turbo). All the research I did showed this was a top quality car that felt like it cost a lot more than it did. Plus it is hands down the best looking sedan on the market at the moment. It looks killer.
Bought the car, great price, 0% financing... quite honestly it was a dream to purchase. I drove it home and was very happy with the 38MPG sticker on the window. I never expected 38... but 33 surely should be reasonable right? Wrong. My first tank I calculated at 24MPG. 24!!!!!!! I called into the dealer and was informed that the new boosted motors require a break in period of about 3,000 miles before they start to get better mileage. After 4,000 miles my best tank was 26MPG. At 6,000 miles I was getting almost 28 when I drove like an old lady. Today that's where my MPG sits.... 28. The car is amazing and I love getting into it every morning but the mileage I get completely screws my cost of ownership numbers. I've learned to live with the shit mileage (my last Honda 2 door got 35mpg) and the car still won't be a loss on my 10 year figures especially with the 0% financing I was able to snag. Just every time I fill the tank I feel like I've been screwed a little.
Depends on where you live, around me in the winter we regularly deal with weather conditions which would stop ultra compact cars in their tracts. During last years winter (admittedly a rather harsh one) it was over a week before our road was plowed on several occasions. I drive a mid size SUV and was able to get through most of it without issue, a family member driving a ford focus couldn't make it out of the drive most of the time. In some areas after they did plow the drifts were taller than my car.
What possible benefit is there to taxing fuel, other than to hand more money to the government to waste?
There are two primary benefits:
One is that the amount of fuel used is a reasonable proxy for the amount of driving that is occurring and thus matching tax revenues with road maintenance costs. If you are going to have cars driving on roads then you need a source of tax revenue to pay for said roads. A fuel tax is really the best way to calibrate road use with tax revenues. (Note I said fuel and not gasoline or diesel - I fully expect electricity to be taxed to pay for roads should electric vehicles become a meaningful percentage of the cars on the road)
The other (more indirect) benefit is that by making fuel more expensive it influences purchasing behavior in ways that result in improved fuel economy and reduce pollution. Less fuel burned = money available for other productive uses. Less fuel burned = less particulates and greenhouse gasses. Less fuel burned = less need for the government to tax you.
My personal favorite is how Americans measure pressure (such as in tires): pounds per square inch. It is so bizarre, it is beautiful...
The "pounds" are pounds of force (lbf), of course, but I doubt, an average person (be he American or European) can articulate the difference between mass and weight...
In Soviet Washington the swamp drains you.
The places I want to go are NEVER on the direct route between A and B. Oregon sunstones are more than 70 miles from the nearest gas station, and the last 30 miles are gravel. That's 140 miles of poor gas milage with no chance for a fill up.
Back roads to trail heads at Paulina Lake, into the Strawberry Mountains, or the fossil beds are even worse.
Once you get out of Mama's basement, there is a wonderful world out there to explore. Using MPG rather than some other fuel consumption measure makes those explorations just a little bit easier.
Will
we should be using gallons-per-mile instead of miles-per-gallon, too.
Wrong. Neither is inherently better.
I have half a tank of gas (6 gallons) and want to know how far I can go before I have to get gas. I get 40 MPG or .025 GPM. 6 * 40 is an easy calculation that most people can do in their heads. 6 / 0.025 is not an easier calculation for most people.
There are specific cases where one or the other figure makes the math easier, but neither is universally better in all cases. Arguing that one figure is better just proves that you haven't thought the question though.
I get miles remaining until empty on the trip computer park of my Volvo, but it can vary dynamically.
For example, if I've just driven a whole tank of fuel on a long highway trip and I stop to refill, the miles remaining indicator goes up to reflect using the tank at basically highway MPG. If I start driving around town, that number starts to drop off with my MPG dropping off due to stop and start driving.
It can go up, too, if somehow I drive the first fraction of a tank at stop and go speeds but then get on the highway (but I rarely see this because I'd generally fill up before a long trip).
It would be helpful if the miles-remaining-until-empty value would also display the MPG value the figure is based on so you'd have some idea on what to base it on.
Mostly it just doesn't matter, though, since gas is so easy to get and I never drive through some kind of barren wasteland where 20 miles makes a difference.
Really, with all the car telemetry systems out there, they should really just crowd collect MPG stats once the cars hit the road and have the average reported as the fuel efficiency numbers.
My God can beat up your God. Just kidding...don't take offense. I know there's no God.
That the manufacturers try to cook the efficiency numbers is nothing new — and various measures exist, no doubt, to keep such padding in check.
Could it be, that these checking measures are deliberately relaxed to encourage the buying public to buy smaller vehicles? It is a perfectly safe for the bureaucrats to do — the blame for discrepancies always falls on the car-makers (who certainly deserve it).
And it need not be obvious — a manager in charge can sabotage any initiative in subtle ways: like appointing an incompetent (or dishonest) subordinate to run it, for example.
In Soviet Washington the swamp drains you.
If you try to push a small engine to drive like a larger one, you'll be accelerating harder, therefore using more fuel than under normal acceleration.
I'm just trying to achieve normal acceleration
For what it's worth, the physical interpretation of this would be that a car with a fuel economy of a given area would be able to drive without needing on-board fuel storage if it were following a trail of fuel with that cross sectional area.
which would make it the ideal measure for something like a ram jet.
Some drink at the fountain of knowledge. Others just gargle.
"But then, we should be using gallons-per-mile instead of miles-per-gallon, too".
No. You should be using litres per kilometer. Especially so when talking about the EU.
And the rest of the world should convert to Islam, because that is the religion I like. But you wouldn't like that, now, would you? So fuck off and quit your crying.
The places I want to go are NEVER on the direct route between A and B. Oregon sunstones are more than 70 miles from the nearest gas station, and the last 30 miles are gravel. That's 140 miles of poor gas milage with no chance for a fill up.
Back roads to trail heads at Paulina Lake, into the Strawberry Mountains, or the fossil beds are even worse.
Once you get out of Mama's basement, there is a wonderful world out there to explore. Using MPG rather than some other fuel consumption measure makes those explorations just a little bit easier.
Quite apart from the random ad hominem, saying that we should use MPG because it's marginally more useful for a tiny share of total trips taken in the US, and only in those cases for the small portion of cars that don't have distance to empty available, and for the drivers of those cars who can't be bothered to fill up at a gas station before venturing out on a 150 mile round trip, just doesn't make sense. Somewhere, there might be someone who has once made a trip in a car where the odometer had been customized to read in rods, and the only local gas station had a software problem with the pumps, so they read in hogsheads for a day. That doesn't mean Grandpa Simpson was right.
Finally, using MPG doesn't really tell you anything for the purpose you're talking about. You care about RANGE, not fuel economy. If you're starting off on that 140 mile round trip without gas stations, and your gas gauge reads half full, and your car gets 25MPG, you could be in great shape (if you have a 20 gallon tank) or screwed (if you have a 12 gallon tank).
As a homeowner with several dogs and who relies on wood heat in the winter, having a truck is pretty much a necessity. But we also have a small car for commuting, because hey, why spend more on gas than you have to?
But I've long noticed that the disparity in gas mileage between the (unloaded) truck and the 4-banger to be much less than their ratings would indicate. Part are driving habits, of course. I tend to be very soft on the gas pedal of the truck, as it just gulps gas if you let it. And the tendency in the econodeathbox is what some people call "the digital pedal", which really has only two states -- idling/decelerating or trying-to-catch-up-with-traffic. All these things tend to have a leveling tendency, probably.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
The #1 selling vehicle in the US for the last 30 years is a V8 Ford F-150.
I have an Ford F-150 and paid the extra $1800 for the Ecoboost 3.5l direct injection, twin turbo motor. The manufacturer's EPA estimate stated 22mpg on the highway. I have taken the truck to a deserted flat stretch of road and tried every scenario, 45mph, 50, 55 etc. The most fuel efficient speed is 53mph in 6th gear. The truck get 18.9 mpg at this rate. The in town is closer with average daily commute registering 16 on a stated 17mpg. How are they allowed to not even be able to reproduce the number under any condition? Furhtermore those money wasters at the EPA charge a fortune to the tax payers for this service and in the fine print state they do not even test the actual cars. This is a fradulent services by the EPA to make sure they have enough money for cocktails in Las Vegas and also false advertising by the automotive companies for putting this in 70 font on the window of a new truck.
EU numbers are well known and documented to be extremelly optimistic. So much so that nobody even cares about them when buying a car. The DOT numbers are much closer to the reality (if still overstating a bit, not by a big bit). Making the correction because europe does not use MPG, so it seems there was some sort of confusion that the overstated numbers were relevant in the US where MPG are the unit of the land.
Smaller cars have smaller engines.
Smaller cars are generally cheaper.
Smaller cars buyers have generally a more restricted budget.
--> They give more attention to advertised mileage.
--> Advertised mileage is a more important commercial argument for smaller cars, since customer are more concerned about their budget.
By the way, I'm driving a Dacia Logan MCV. It has the same engine as smaller "Renault Clio 2", though it is bigger (7 seats). It has a smaller engine than the "Renault Megane" (smilar sizes). But it has a very different gearbox. Advertised mileage is higher on the Dacia Logan, but more realistic when driving on mountain road. Renault's car can be really irritating cars when climbing, beacause the gear box is designed in a way it sacrifices the torque to give a lower mileage on flat road.
The point is that in Europe, advertised mileage can not be reach unless you drive only on flat straight road. Which you can find in Holland and Belgium. The impact of mountains or city driving can completely change which car is the most "ecological", because if engine's size does matter, it is not the only factor to consider.
You can find it yourself. I use "Torque Pro" app (by Ian Hawkins) and load the OBD2 logs to autotalky.com. With proper configuration your car will notify you via email or SMS what your real MPG / KPL is per trip
This was deliberate, to screw manufacturers with bigger engines.
Well said. It is all about RANGE: how many miles one can go on a gallon of gas. That is a measure of range. Whereas liters per 100 km or fluid ounces per mile is about engine efficiency, and has to be converted to be used in range estimations.
Will
Late at night, in the wee hours, a hand sneaks out of the gas cap and gently rubs the engine. For a short period of time, the car has the same size engine as the other cars.
Okay, now we just need a joke about black cars, and maybe Japanese cars.
Giving measurements in gallons per 1,000 miles would yield a number that is easier to understand. And using the measure would probably make a huge difference in people's car buying decisions Most people would intuitively assume that going from a 15 MPG car would yield the same fuel savings as going from a 25 MPG car to a 30 MPG, but it doesn't. The efficiency gains from getting rid of the least fuel efficient cars are massive compared to the marginal gains from going from an ok car to an even better car. For example, going from a 15 MPG car to a 20 MPG car would save 17 gallons per 1,000 miles. Going from a 25 MPG car to a 30 MPG car would only save 7 gallons per 1,000 miles. We don't need more Priuses on the road, what we really need are fewer Suburbans and Hummers. This blog post explains it pretty well. From the linked blog post:
An example might help show how big a difference using GPM can make. There are about 250 million cars in the United States.4 Cars in the United States average about 17 MPG.5 To simplify things, let’s imagine a hypothetical world where all cars in the United States either get 30 MPG or 10 MPG. To get an average of 17 MPG, this would mean that there would be 87.5 million cars that get 30 MPG and 162.5 million cars that get 10 MPG. Assuming that people drive an average of 900 miles per month, in our hypothetical example the United States would be using 17.28 billion gallons of gasoline per month.
Now let’s assume that we want to increase the country’s average MPG to 20, but only by changing one of the two types of cars. If we did this by increasing the MPG of the 30 MPG cars, we would have to increase them to 38.5 MPG. After this change, the total fuel usage would be 16.67 billion gallons per month, which would save 584 million gallons of gasoline.
If we decided to increase the MPG of the 10 MPG cars (but leave the 30 MPG the same), we would have to increase them to 14.62 MPG. After this change, the total fuel usage would be 12.63 billion gallons per month, which would save 4.65 billion gallons of gasoline. The net change in average MPG would be the same, but increasing the efficiency of the 10 MPG saves almost 8 times more fuel than changing the 30 MPG cars.
you have no idea about my rod
Bingo Dictionary - Pragmatist, n. A myopic idealist.
Is why those numbers are overrated. For example if my Porsche turbo only gets 16 mpg because it's stupidly fast and sporty I won't have to mash the gas to the floor when I am ina hurry. If you have 3 cylinder shit box that gets 45mpg but takes 40 seconds to get to 60mph the Ill have to basically stand on the accelerator to keep up with or pass any other vehicle.
I bought a 2013 Dodge Caravan new. Its mileage is rated at 17 city 25 highway. I have gotten as high as 31 MPG on a (very level) freeway and generally about 28-29 on a long trip with some mixed terrain. The people at the dealer seem unsurprised. I drive at freeway speeds, usually 70-75 MPH. City mileage is 17-19.
Not being a car buff, I can't even think of why, outside on-track racing, you'd have any need for such a huge engine in a personal vehicle. That's up in the engine size range for articulated freight lorries.
Or is it, in the words of Madame Sin, a case of "big car small dick"?
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
It is even worse if you do go the direct route if that route does not include interstates and major highways which is often the case and some major highways do not have fueling stations either for long distances. It does not take not having a gas station within a maximum linear distance. It just takes missing it because it was on an even more minor road.
You might for instance think it is difficult to find a south to north "direct" route from Los Angeles to San Fransisco which would be marginal in a car with a 250 mile range yet I managed to do it. It was scenic but worrying toward the end before I spotted a fueling station. This was before ubiquitous GPS mapping and cellular data service although cell coverage was marginal at best anyway along that route and probably is now.