Wechicles equipped with a high horsepower motor use more fuel more than most motors. What does the federal gonverment impose on these vichiles

2 answers

http://www.fueleconomy.gov/feg/info.shtml#guzzler
Some states and foreign countries impose a "gas guzzler surcharge" tax or "surtax" on such vehicles. The federal government is thinking about it, and is also fighting the states' rights to impose such taxes.

A Google search of the words gas guzzler surcharge will get you a lot of references on this subject.

Auto makers are also penalized for selling so many gas guzzlers that their "fleet average" gas mileage is less that federal requirements of 25 mpg.