The Horsepower Game is Full of Hot Air
One of the things that really irks us is false advertising. How can someone claim "4 hp" and then supply a product that is just about 1hp? Basic known energy facts do not fail to exist with regards to motorcycle dryers. Here is a basic lesson on electrical and mechanical power:
1 Hp is defined electrically as 746 watts of power. There can be some argument whether that is energy used or energy delivered. Nevertheless, if the motor was 100% efficient, the 746 watts into the unit would develop 1hp. (The types of motors used in motorcycle dryers are about 35% efficient). So if a dryer was 4hp and 100% efficient, it would take 4 x 746 watts or 2984 watts. To determine amps, simply divide 2984 by 120 volts which gives us 25 amps. Therefore, the least amount of amps needed to give 4hp on a 120 volt circuit would be 25 amps. Yet these "4hp" motorcycle dryers only take 9.5 to 10 amps of power. How can that be? Remember, that is assuming a 100% efficient motor.
Here is our advice: Ignore the "HP" rating on motorcycle dryers. They are misleading and only hope to trick you into believing a certain motorcycle dryer is more than it is. The only thing that is "4hp" on those dryers is the label.