Ask The Best And Brightest: Which Automaker May Be Fudging Their EPA Numbers?

Edward Niedermeyer
by Edward Niedermeyer

The Environmental Protection Agency’s fuel economy testing system is notoriously weak, relying on self-reporting for the vast majority of vehicles, and exhibiting vulnerabilities to “gaming.” But rather than attacking each others’ EPA numbers, automakers seem to have agreed that it’s best if everyone does their best to juice their own numbers and allows the imperfect system to limp on. But over at Automotive News [sub], we’re hearing what could be the first shots fired in a new war over EPA ratings, as Product Editor Rick Kranz reveals that an OEM is starting to complain about another OEM’s fuel economy ratings. He writes:

An executive of one U.S. automaker suggests there might be some sleight of hand going on and that the EPA is not catching the offenders.

The issue: There’s a noticeable difference between the mpg number posted on some cars’ window sticker and an analysis of the data submitted by automakers to the EPA.


Kranz continues:

The executive raised a red flag earlier this year. He told me his company was unable to replicate the city, highway and overall fuel economy numbers achieved by some automakers for their 2011 car models.

He didn’t name the automakers or the car models in question. Neither would he give the percentage differences between the mpg numbers posted on new-car window stickers and an analysis of the data taken from dynamometer readings his company purchased for certain competing models.

But he said consumers are being misled. The mpg numbers on some window stickers or in advertising are being misrepresented, he said.

Here’s the thing: if an executive is complaining about another OEM gaming the EPA test or somehow fudging its results, this executive must be extremely angry or frustrated. After all, a weak EPA testing regime benefits all automakers at the expense of customers. And if someone is willing to blow down the EPA’s house of cards, there’s no knowing where the fallout could end. There are basically three possibilities:1) The accusing executive has the wrong end of the stick, and is just lashing out without cause.2) The accusing executive is on to something and an automaker is fudging its EPA numbers.3) The accusing executive is on to something, and he’s just scratching the surface of a problem infecting a large part of the industry.As fuel economy becomes a bigger factor in car-buying decisions, the EPA needs to recognize that there is more riding on its weak, “faith-based” fuel economy testing regime than ever. It should not only investigate this allegation, but it should perform supplemental targeted verification tests on vehicles with “suspiciously high” fuel economy ratings. Consumers need to trust their window stickers, and if there are rumors of gamesmanship around the production of those numbers, competitive pressure will spread deceptive practices around the industry. This needs to be nipped on the bud.So, in hopes of helping the EPA get a handle on this situation, I ask the B&B to share their thoughts about what automakers might be fudging their numbers. What vehicles would you spot-test to see if they can achieve their window sticker numbers?

Edward Niedermeyer
Edward Niedermeyer

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  • Doctor olds Doctor olds on Sep 03, 2011

    EPA Mileage ratings are simply derived from the Federal Test Procedure emissions chassis dyno test. The actual amount of fuel used is not measured, but calculated from the tailpipe emissions numbers. The FTP offers a controlled and reasonable way to compare one vehicle to another on that specific drive procedure, not necessarily in the real world. If memory serves, the vehicle never exceeds about 50 MPH on the FTP. The actual numbers generated by the FTP were substantially higher than consumers achieved in real use. TTAC has covered in a general way the fudge factors used to generate the current, adjusted lower window sticker numbers. Real world usage is not constrained to the acceleration rates and maximum speeds of the FTP. Powerful, heavier cars can be quite a bit worse than the EPA estimates, as owners typically use the power to accelerate faster than the FTP.

  • Rpn453 Rpn453 on Sep 10, 2011

    This could be coming from Mazda. They've outperformed many other makes with higher EPA numbers in CR, C&D, and MT fuel economy testing. I lost faith in EPA numbers when the Equinox's were shown to be inflated. I no longer consider them a factor when it comes to evaluating vehicles.

    • Bytor Bytor on Sep 10, 2011

      The big Equinox buzz was the highway MPG. Which they actually achieve at CR: CR only tested the the AWD version rated at 29 MPG highway. CR got 30 MPG highway. It seems very likely that the FWD version would have matched the claimed 32 MPG. But still the number is close that there may be a slight bit of fudging. Usually a cars CR highway MPG will beat the EPA number by 10%. Still to this day they only car I have seen not make their highway numbers on a CR test is the Hyundai Elantra, which is Fudged at 40 MPG for marketing purposes. This is the one Ford complained about as well and rightly so IMO.

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