Light truck is a vehicle classification generally used by the United States government for regulating fuel economy and safety. The class includes vans, minivans, sport utility vehicles, and pickup trucks (for which the class is named). Light trucks are allowed to have lower fuel efficiencies than cars, since the classification originally referred to vehicles that generally carried fairly large loads on a regular basis. However, since SUVs and minivans are usually used for moving people, some people (especially environmentalists) have advocated splitting the class. Additionally, many have accused auto manufacturers of using dirty tricks with the light truck class to skirt fuel economy regulations, since the more fuel-hungry vehicles can easily influence Corporate Average Fuel Economy (CAFE) with relatively small changes. For example, almost all of the flexible fuel vehicles made for the U.S. market that can run on 85% ethanol are light trucks.