Why are EPA milage estimates so wrong?

[mikelish]

Have the car companies figured out how to trick the EPA into giving them high estimates?

Almost every new car gets much lower actual mpg than what is listed on the sticker.

 

[ElFenix]

Have the car companies figured out how to trick the EPA into giving them high estimates?

Almost every new car gets much lower actual mpg than what is listed on the sticker.

well, yes, they have figured out how to game the test a bit.


as to what cars getting what, what's your source?

 

[sandorski]

People don't drive in the same way the Tests are conducted.

 

[jlee]

My Forester XT is rated for 16/22. I usually get 20-21 mixed - best of around 24mpg, average on long highway trips is 22ish. That's with a bigger turbo, intercooler, exhaust and a tune.

 

[MotF Bane]

Straight road, perfect tires, a feather on the gas pedal, and a stiff tailwind.

 

[PricklyPete]

Have the car companies figured out how to trick the EPA into giving them high estimates?

Almost every new car gets much lower actual mpg than what is listed on the sticker.

My wife's 2010 A4 gets significantly better gas mileage than it is rated at. It's highway mileage is 27mpg and we regularly get 33+ (that is actual measurements...not just the computer where it says we get 34-35). I've been quite happy with this.

 

[Demo24]

I tend to feel the EPA estimates are pretty solid, if not a bit conservative at times. Meanwhile the euro ratings seem to be rather optimistic in comparison. But you can't expect a car to always match it's ratings. That will change drastically depending on driving style, location, and upkeep.

 

[LTC8K6]

My Jeep GC with the 5.7L and cylinder deactivation does quite a bit better than the EPA rating, both by the dash reading and by calculations.

The estimates are for comparing vehicles in classes, not for guaranteeing what a particular vehicle will get. Every engine and trans are a little different. Tires vary. Fuel varies. Terrain varies. Habits vary. Etc.

 

[mikelish]

everyone so far has evidence going against my OP.

so maybe i'm wrong.

but my sources were Chevy Equinox which lists 32 highway but I heard it gets in the 26mpg highway range.

also the Kia Sportage lists 29mpg highway but supposedly gets closer to about 24mpg.

 

[LTC8K6]

everyone so far has evidence going against my OP.

so maybe i'm wrong.

but my sources were Chevy Equinox which lists 32 highway but I heard it gets in the 26mpg highway range.

also the Kia Sportage lists 29mpg highway but supposedly gets closer to about 24mpg.

Sometimes when the mfg puts a small engine in a largish vehicle, drivers end up flogging the hell out of it to get it to move, which kills the average mileage.

I think this will be the case with the Ford Explorer and the 2.0T, for example.

 

[punjabiplaya]

hwy rating is 25, I usually get about 27-28 mpg for the whole tank

it really depends on the manufacturer. Even hp/tq ratings can be off by 10% (BMWs x54 motors come to mind)

 

[C101]

The EPA estimates for my car are 22 city, 31 highway, and I regularly see high 20's for city, and on my cross country drive this summer I saw up to 43mpg highway. Always above 40, except when I was climbing the Rockies, then it was only 36.

 

[Eli]

Er? The EPA estimates are supposed to be better now than they were several years ago. Almost all cars lost several MPG due to the new testing procedures.

But yeah, the EPA tests are based on a standardized test. Obviously, YMMV.

 

[T2urtle]

the NEWER EPA ratings from sites like fueleconomy.gov is actually not too far.

There are normally side notes and they take averages. like city is rated 18 but thats because its 14-21mpg or w/e it actually is. And highway is based off at 55mph speeds, of course if your car is has a bad alignment, stickier tires and stuck brake calipers your not getting that.

Fuel economy numbers are only averages and guesses. I find them on par.

 

[LTC8K6]

http://www.caranddriver.com/features/09q3/the_truth_about_epa_city_highway_mpg_estimates-feature

 

[RU482]

everyone so far has evidence going against my OP.

so maybe i'm wrong.

but my sources were Chevy Equinox which lists 32 highway but I heard it gets in the 26mpg highway range.

also the Kia Sportage lists 29mpg highway but supposedly gets closer to about 24mpg.

notice the magic words bolded.
there are alot of claims of MPG out there for cars that I have owned that I was never able to get within 25% of. Example claims like 98 Pontiac Bonneville getting 36MPG, meanwhile when I owned one I was lucky to get 28MPG. meh, the internet (and people, for that matter) are filled with misinformation.

 

[HybridSquirrel]

EPA ratings you see are the averages, not the actual range you will get. You could get 34 MPG highway on the sticker, but it will say "average drivers get between 25 and 40mph highway)".

 

[brblx]

1) people suck at driving
2) not all engine control systems are created equal. if one can do way better than the EPA estimate with normal driving, there's probably another that struggles to even match it. (not because its crap but because of different levels of tech)

A lot of it has to with optimally sized and cotrolled engines. you can easily burn more gas winding out a 4cyl than driving a v6 or v8, assuming the positive attributes of the bigger motor are properly utilized.

highway ratings are what i never really got. i expect city to be weird, but given the realtively static weight and aerodynamics of a car, it seems like these numbers wouldn't be that hard to get right(ish). just have to spend a little time driving at interstate speeds on flat ground.

 

[LTC8K6]

http://www.fueleconomy.gov/mpg/MPG.do?action=mpgData&vehicleID=30505&details=on

 

[JulesMaximus]

My Maxima gets about what it is rated, the trip computer on the other hand is consistently overly optimistic. My wife's Lexus also gets the rated mileage.

 

[ElFenix]

the NEWER EPA ratings from sites like fueleconomy.gov is actually not too far.

There are normally side notes and they take averages. like city is rated 18 but thats because its 14-21mpg or w/e it actually is. And highway is based off at 55mph speeds, of course if your car is has a bad alignment, stickier tires and stuck brake calipers your not getting that.

Fuel economy numbers are only averages and guesses. I find them on par.

no, it's not. even before 2008 it used 60 mph and now they have an additional high speed test with up to 80 mph speeds.
http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

 

[punjabiplaya]

in short: EVERYONE DRIVES DIFFERENTLY UNDER DIFFERENT CONDITIONS

 

[SearchMaster]

My last two cars have gotten better mileage, in mixed driving, than the new EPA highway rating. My commute has a lot of fairly open stretches of road but a fair amount of stop and go as well. How you drive has a lot to do with its MPG.

The Equinox example may be a poor one because it's been suggested that its transmission was tuned for the EPA test more than the real world.

 

[alfa147x]

My current and older civic both beat the EPA estimates

 

[Zenmervolt]

everyone so far has evidence going against my OP.

so maybe i'm wrong.

but my sources were Chevy Equinox which lists 32 highway but I heard it gets in the 26mpg highway range.

also the Kia Sportage lists 29mpg highway but supposedly gets closer to about 24mpg.

The issue is that most people simply don't understand how much of their driving is really "city" cycle and not actually "highway." The only time you really get a tank full of "highway" driving is when you're making a 400+ mile trip on the interstate. A daily commute, even if it's on the freeway, isn't going to get you close to the EPA highway rating over the course of a full tank.

For example, I have a 22 mile (one-way) commute. All but 2 miles is "highway," that is, it's signed for 55 mph or more. The problem is that those 2 miles are full of stoplights. My average for a tank is only about 21.5 mpg when I'm commuting. When I run free on long road trips, however, I'll get 26-27 mpg, but that means absolutely zero stop-and-go traffic. People simply don't realize just how much affect a very small bit of city driving will have on mileage.

ZV