The formula below is used to calculate engine horsepower (hp) from wheel horsepower (WHP).
HP = WHP * 1 / (1 – DL )For front-wheel drive, the drive train loss is 10%; for rear-wheel drive, it is 15%; and for all-wheel drive, it is 25%.
WHP stands for wheel horsepower and HP is typically used to refer to the true engine horsepower output. The difference is where the power is measured.Engine horsepower is measured at the flywheel, whereas wheel horsepower is measured at the wheels.The wheel horsepower number is typically 20%-45% lower than the engine horsepower number.