After a number of automakers having to revise their fuel economy estimates, the Environmental Protection Agency is proposing that automakers run their vehicles in the real world to see if their estimates hold any water.
"Some auto makers already do this, but we are establishing a regulatory requirement for all auto makers," said Chris Grundler, director of the EPA's Office of Transportation and Air Quality.
The EPA's proposal would have automakers run their vehicles on a test track to measure air-resistance and rolling friction. At the moment, most automakers use computer models to generate this data. But if the wrong data is put in, it could cause mileage numbers to inflate, such was the case with Ford in their most recent revision.
The EPA does note that a few OEMs do real world testing, but it hopes that it can make the testing a requirement for all.
Source: Wall Street Journal (Subscription Required)