Mark Fields, Ford‘s COO, says the brand is following EPA rules in certifying its vehicles fuel mileage. Recently, Consumer Reports scrutinized Ford for falling to deliver on mpg promises, but Fields said that isn’t the company’s fault.

“Our testing procedures are in line with the testing protocols the EPA has laid out – and importantly our customer satisfaction in the vehicles that we sell, fuel economy is very high on the list,” he said to the Detroit Free Press. “We’re quite satisfied that we’re following the appropriate rules.”

Consumer Reports tests suggested the Ford C-Max hybrid’s highway fuel economy is 37 mpg; 21 percent worse than the EPA’s 47 mpg rating, which Fields claims he isn’t familiar with. Fields said customers seem to be satisfied with their cars and that fuel consumption depends heavily on how drivers behave.

Besides hybrids, Consumer Reports  recently released a list of its own fuel economy findings that highlighted how small turbocharged engines might not necessarily keep their lofty promises. Automakers are quick to brag about the turbo powerplants as delivering power like a larger engine wile consuming less fuel.