Brake horsepower definition
(BHP) A measurement of the actual usable power (not calculated power) measured at the output shaft (usually the crankshaft ) rather than at the driveshaft or the wheels. Thus none of the auxiliaries (gearbox, generator, alternator , differential , water pump, etc.) are attached. It is called the brake horsepower because the shaft power is usually measured by an absorption dynamometer or "brake." This is not the brake on the car's wheels but a testing device applied to the shaft. This instrument is applied to stop or absorb the rotation of the output shaft and returns a value. Compare S.A.E. gross horsepower and S.A.E. net horsepower . Also see Horsepower .