when i put my car in reverse the interior fan blows harder anyone else noticed this?

They all do, so that it doesnt suck exhaust fumes inside the car.

thanks dude

I've always noticed this but never thought much of it or to ask why. Now that I know the answer, its quite interesting.

Out there, somewhere there is an engineer who thought of this idea; he is probably thinking to himself his amazing invention isn't appreciated much....and he is probably correct, well in the most part anyway

Mike.

Aye, it switches to recirc when you select reverse - very clever idea!