The Environmental Protection Agency in August announced a plan to freeze fuel economy standards and revoke the ability of California to set more stringent rules than the national ones, prompting a legal showdown between the state and the federal government. The proposal, which would keep fuel economy at planned 2020 levels, is the most significant step to halt the rise on the mileage standards of the U.S. passenger vehicle fleet in decades. But how did fuel efficiency even become mandated? After all, manufacturers go to great lengths to analyze the consumer marketplace and build in the most tantalizing features to create top sellers, whether it’s great acceleration or a deep bass sound system. One feature is different, though: Carmakers are legally bound to innovate more efficiency into their vehicles. The regulations requiring higher efficiency – known as the Corporate Average Fuel Economy standards – are one of the clearest […]