All cars lose a percentage of power through the drive train. All car manufacturers say that their engines produce "X" hp but what they fail to neglect to mention how much the transmission and other gear boxes (if applicable) eat up. Not to mention all cars are different so each one's drive train will eat up a different amount of power.

That is just what I learned growing up if anyone cares to correct me by all means do so now as I am not an expert.