Chrysler dropped a bombshell today, insinuating that its forthcoming 2013 Dodge Dart will have a combined fuel economy of 40 miles per gallon. Some media outlets have regurgitated this number without question. But it just isn't true, as that 40-mpg fuel economy number is unadjusted and will most certainly be lower once it gets printed on window stickers.
To better understand the way fuel economy numbers get calculated, we'll point you to this page on the Environmental Protection Agency's website. The short version is that cars are tested by the EPA to determine fuel economy for Corporate Average Fuel Economy (CAFE), then adjusted for real world conditions before they are published, both on the EPA website and on Monroneys, or window stickers. City numbers are dropped by 10 percent, while highway numbers get a 22-percent reduction. Some rough estimating says that the Dart will probably be rated at about 34-mpg combined once the final adjustments are made. Still a good score, for sure, but far from 40.
So why did Chrysler even mention 40? In its big announcement today that Fiat had increased its ownership stake, the explanation is that Chrysler has met one of the conditions of the bankruptcy agreement, that it produce a 40-mpg vehicle for CAFE. That vehicle is the Dart.
Could Chrysler have done a better job of explaining what the fuel economy number really means? Sure, but then we wouldn't have been able to write this post.