'For one thing, federal policy has, in many ways, distorted the car market to favor larger vehicles. Fuel economy regulations, for instance, are more lenient for SUVs and pickups than they are for smaller cars, nudging automakers to produce more of the former and fewer of the latter. Another egregious example: Small business owners such as real estate agents can save thousands of dollars by writing off the cost of their vehicle—but only if it weighs more than 6,000 pounds, a stipulation that effectively excludes sedans entirely.'
Fuel economy standards are being used as a tool to get rid of gasoline-powered sedans. Environmental activists generally support this.