most nascar cars hp
Quick Answer. NASCAR stock cars were previously allowed 850 to 900 horsepower; however, this amount was reduced to 725 horsepower in 2015. The lower horsepower is used with a tapered spacer, which is used in the NASCAR Nationwide series. In addition, the 2015 rules include a reduction of 6 inches on the rear spoiler, which cuts down on the downforce for drivers.