Between consumer tastes and government mandates, automakers have been scrambling to offer more fuel efficient vehicles. The pressure led to some overly-generous MPG ratings, which in turn led to lawsuits and downwardly-corrected MPG numbers. Now the EPA wants to take a closer look at the testing methods used by automakers, reports Automotive News.

Ford and Kia/Hyundai have taken the hardest hits from consumers complaining about lower-than-expected real world MPG ratings, which has led the EPA to reevaluate certain testing procedures. Under particular scrutiny is the 80 MPH “coast down” test, which is designed to testing aerodynamic friction by having the car cost to a stop from highway speeds. Automakers apply this test differently, leading to more favorable MPG ratings that have become something of a scandal over in Europe as well.

Also under consideration is the closure of a loophole that allows cars with similar weights and drivetrains to get the same fuel economy ratings without further testing. The EPA will also commit to doing more MPG audits, as automakers are basically placed on an honor system when it comes to MPG ratings, with the government agency testing just a small fraction of the cars for itself. This loophole allowed Ford to apply higher-than-expected ratings to the C-Max Hybrid, though once it went back and re-tested the car (and others) it found that the coast down test was giving its cars a higher rating than it ought to. Ultimately the Blue Oval was forced to correct the MPG ratings of six vehicles, which hurt sales of the C-Max particularly hard.