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Consumer Watchdog Asks White House, EPA, to 'Clean Up Doubts' on Clean Air and MPG Tests, Bring Them In-House

fuel guage

Wide Gaps in Claimed and Real MPG Put U.S. Automakers at a Disadvantage, Says Letter

WASHINGTON--Jan. 12, 2012: In conjunction with the National Auto Show in Detroit, Consumer Watchdog has sent a letter to the White House with data showing that in real-world driving the Chevy Cruze ECO got 28% better overall MPG than the highly touted 2011 Hyundai Elantra, even though the two models received the same EPA combined mileage ratings. Such disparities between tested and actual mileage, including similar shortfalls in MPG that generated lawsuits against the Honda Civic hybrid, are likely putting domestic automakers at an unfair marketing disadvantage to foreign-based competitors, said the group. This is important for U.S. taxpayers who still own a 25% stake in General Motors after the 2009 federal bailout of GM and Chrysler.

Almost all clean air and MPG testing is done by manufacturers, not the EPA (which merely certifies the results). Given the questions about tested and real MPG, Consumer Watchdog asked President Obama to require the EPA to bring clean-air and MPG testing in-house to increase consumer confidence, and to also reevaluate its testing procedures.

See the letter at Consumer Watch Dog

The letter said, in part:

"Consumers are largely unaware€”and would be shocked to know--that the Environmental Protection Agency does not conduct most auto clean air and MPG tests. Manufacturers conduct the tests themselves and transmit the results to the EPA, with a low likelihood that the EPA will re-test to confirm validity. In fact, though the EPA has told Consumer Watchdog it will keep our findings about the Elantra in mind in future testing, it declines to re-test current and previous year models. Manufacturers' post-market engine modifications, like those made by Honda on earlier Civic hybrids to extend engine life at the expense of MPG, also apparently do not trigger a requirement to re-test the auto or notify buyers of MPG degradation.

"It is past time to bring MPG and clean air testing back to the EPA itself. This is the only way to prevent manufacturer gaming of the results [and] clean up doubts caused by the EPA's dependence on manufacturers"

"With gasoline prices stuck at historic highs, a few miles per gallon can tilt a buyer's decision between similar cars in the same class. If a domestic car is slightly more expensive or has slightly lower official MPG numbers than the competition, but actually gets better on-road mileage, the scale is tilted against the U.S. manufacturer. This appears to be factually the case in comparing the Chevy Cruze and the Hyundai Elantra. The table at the end of this letter, based on driver self-reports at, shows:

  • The Cruze ECO overall achieved nearly 28% better MPG on-road than the 2011 Elantra, even though both models' EPA estimated combined mileage is an identical 33 MPG;
  • The Elantra fell below its EPA 33 MPG estimate for combined driving by 12% for the 2012 model and 7% for the 2011 model;
  • The regular Chevrolet Cruze exceeded EPA estimates of 28 to 30 MPG combined--in 2012 by 3% and in 2011 by 7%.
  • The Chevrolet Cruze ECO was even better at 12% above its 33 mpg combined estimate in both 2012 and 2011.

"If a shopper looks at two similar cars of nearly equal price and one claims three or four more miles per gallon in combined driving than the other, as is the case with the Elantra and the Cruze, the smart driver will pick the more efficient car," said Judy Dugan, research director of Consumer Watchdog. "But if the car with lower MPG on the dealer's sticker actually gets better mileage in the real world it's a false choice. Consumers need to know the tests are fair, and that they can get the same result on the road."

The choice has even more weight when taxpayers are on the hook to gain or lose billions of dollars when the government sells its remaining stake in GM, said Consumer Watchdog.

In previous letters to the EPA and Hyundai, Consumer Watchdog noted that in professional tests, Consumer Reports got an overall MPG on the Elantra of only 29 MPG, and Motor Trend, despite naming the Elantra Car of the Year, got only 25.9 MPG.

Previews of Elantra ads for the widely watched Super Bowl all tout "40 MPG," but the caveat that this is only the highway number is in very small print, unmentioned in the voiceover.

The letter said the Honda cases bring up a separate issue:

"The Honda Civic hybrid case was even more clear-cut, in part because of the company's post-sale engine modifications of the models at issue. The claimed MPG for newer Civic hybrid models is lower, now in the mid-40s. Thus the line between hybrid and conventional autos is blurring, which makes it all the more important that EPA-certified MPG numbers be fully dependable from model to model and from one engine type to another. Otherwise drivers cannot make accurate price decisions."

The Auto Show puts new autos, both American and foreign, at the forefront of public awareness, said Consumer Watchdog. The Super Bowl on February 5th will be loaded with automakers' best marketing messages, including MPG making this a good time to reassure consumers that the White House will make sure they get dependable MPG measurements that allow them to make accurate choices.

The chart below, included in the letter, is derived from driver self-reports at These drivers are self-selected for their interest in fuel efficiency, and their reports are likely to put real-world MPG in the best light, said Consumer Watchdog.

Cruze vs. Elantra In Real World: Cruze Bests EPA estimate, Elantra Falls Below


4 cyl.

EPA estimated city/highway

for 1.4 L engine

EPA est.combined

Real driver MPG reports (via

# of drivers reporting

Variance from EPA est. combined

Hyundai Elantra 2012

29/40 MPG

33 MPG

29.0 MPG




29/40 MPG

33 MPG

30.6 MPG



Chevy Cruze 2012

26/38 MPG

30 MPG

31 MPG


+3 %


24/36 MPG

28 MPG

30 MPG



Chevy Cruze ECO 2012

28/42 MPG manual, 26/39 MPG auto

33 MPG

31 MPG

37 MPG (mixed manual, auto)


+12% (at minimum)

ECO 2011

28/42 MPG manual

26/37 MPG auto

33 MPG

30 MPG

37 MPG (mixed)


+12% (at minimum)