There could be a slight teeny .00001 mph  pick up in speed.
There is also the aero affect of blasting that air back, down, and out, it
may help or hinder, like .00001 %.
Top fuel dragsters, the ones that are now doing 320 mph I think in a
quarter, and have 3,000 + horsepower, the downforce created by the exhaust
shooting up is an actual factor, to the good. 
I'm starting to incorporate this in my more powerful subaru conversions now.

  We go to the nth degree of art elegance in fabrication and engineering
here, for the greater glory of vanagons, and the rewarding satisfaction of
their owners. 
Scott
www.turbovans.com 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Loren Busch
Sent: Tuesday, January 22, 2008 12:42 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: LED to tell when fan is on.

You are not alone Al.  I refer to the high speed mode on the radiator fan on
Starwagen 'Propeller Mode'.  I swear I pick up speed when it comes on....

On Jan 22, 2008 12:31 PM, Pensioner <al_knoll@pacbell.net> wrote:

> Neil, perhaps you should have your hearing checked.  When my F111
> simulator
> fan comes on an LED is clearly superflous.  It is shall we say, very
> noticeable.  Maybe I just have a loud fan though.
>
> Pensioner (replaced fan at 190Kmi)
>