E46Fanatics - View Single Post - Mechanical vs electric puller fans...why.....
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Old 02-10-2011, 12:07 PM   #6
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Join Date: Nov 2010
Location: CO
Posts: 125
My Ride: 01 330xi
MarkM-- You're making quite a bit of progress, congrats

The whole clutched fan/ electric fan combo is a throwback to older cars (E34/E32, if not older) All cars had a viscous coupled fan on the water pump shaft, and with a/c you'd get a pusher fan in the front for additional cooling. My manual trans e34 525i had a viscous fan, and on a hot day, believe me I was wishing for an all electric system. The drag on the engine is ridiculous, turning a 525 into a 518..

I think they stuck with it on the autos because of the need to cool the trans fluid, and that the additional drag on the engine is much less annoying when you're not shifting yourself.
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