text: It depends on who is rating it and for what purpose. \n\nGenerally HP is rated at the wheels. This rating is actually ~20% less than the engine HP because of transmission losses, rolling resistance etc.\n\nAll things being equal the more HP the more power the vehicle will have, however more power does not necessarily mean speed especially while getting up to speed and for passing.\n\nTorque is actually more important than HP for speed. A high torque engine is preferred over a high HP, low torque engine. The lower the RPM the engine needs to turn  to obtain maximum torque the fast the vehicle will be able to accelerate and the more efferent the vehicle will be... This is why low HP diesel engines can pull heavy loads... diesels generally have several times the amount of torque of a similar HP gasoline engine and their torque is developed at lower speeds (RPM) than gasoline engines... that is one reason diesels are so fuel efficient vs gasoline engine...\n\nHope this helps.