Quote Originally Posted by tom4bren
I was thinking about this on my way in to work this morning (Hey, it's 45 miles on I95 in some pretty heavy traffic so I had time to think).

I'm don't mean to pee on your charcoal but I just can't imagine it making as much of a difference as y'all make it out to be.

Assume that the electric fan motor is 1/4 HP (reasonable) and that it is twice as efficient as the mechanical (I'm being generous here). The engine is 215 HP. That works out to about 0.1% more horsepower being available to send down to the wheels. Am I missing something here?

All that said, there are some benefits and the mod is worth doing. I'll probably do it too - someday - but we've already established my procrastination status.

Gentlemen, do the swap and enjoy your 0.1% increase in throttle response. LOL.
You are not peeing on my charcoal! I see the potential for increased performance; if you don't, that is your own fire you are putting out. I am about to fit bigger, heavier tires. The tires about 1% bigger and are going to rob some performance. Judging by calculations I have seen over time, your calculations are off. I have read mechanical fans can rob as much as 5 hp. Electric fans may use as much as 2 hp - but they are hardly ever on, so at most times no hp is lost. I have grown accustomed to being overgeared with my 4.77's and would like to offset the torque lost by adding these new tires as much as possible. An electric fan is cheap and easy.