How much does the Volvo fan & clutch assembly weigh?
About the same as the electric one of the same size, I’ll bet. I don’t think the weight diffo would be interesting on a car the size of a Volvo. >>> – How much less of a load on the engine would an electric fan be (in HP)?<<< Depends on the size of the electric motor, I'd guess. I'm no electrician, but the _starting_ load on the electric "helper" fan in my BMW is over 20 amps, though the steady-state is less than 15 amps. 15 A at 12 V is 180 Watts, and 1 HP = 746 Watts ... but this doesn't take into account the loss in generation, conversion, battery charging, etc. It's less that an engine-driven one, though. Conventional wisdom is that a solid-bolted fan is about 4 or 5 HP at highway speeds, and a viscous-coupled one is 0.25 to 4 HP depending on amount of clutch slippage. In theory, on the highway, the power drain of the clutch-coupled fan is very low, since it is operating in air that's moving pretty good, anyway, and (in the case of a heat-sensing clutch) is mostly disengaged. Proba
