Honestly I don't know. There was something about the police fan clutch... like it's equal to the motor at all times. It's like a 1:1 ratio with the motor. Instead of spinning faster only when the engine is running hotter, it spins equal to the motor speed all the time for better cooling? I think it was something to that effect. If you email PPI I'm sure they will tell you exactly how it works. They are good guys and know their stuff about SSP vehicles and parts.