Hi Chris,
I also installed an audi 5000 thermostat in my '90 vanagon.
I am still using the original thermo Fan Switch.
Didn't want the fan to come on constantly.
During freeway driving, the temp.gauge needle used to sit just on top of
the red light. Now it stays below it.
During stop and go traffic, the needle slowly crawls back up to its old
position, which is just on top of the light.
If one compares the two thermostats, you will find that the deflection
shield on the audi 5000 thermostat is bigger. I trimmed mine to the same
size as the original vanagon one. Just wanted to make sure it would not
block the flow of coolant. Used that setup for about a year now.
Still get the same mileage, and the motor seems to like the lower
temperature during those long high speed (relative) freeway runs.

Harald 90 westy

Chris wrote:
>  I have some info that I received recently from a fellow Vanagonut at the
> Porsche 50/50 celkebration at Watkins glenn.. He had taken an Audi 5000
> Thermostat and TFS (Thermo Fan Switch) and replaced the original Vanagon
parts
> with them. He claimed that the car ran about 10Deg lower then with the
factory
> spec parts, I found that to be a great Idea and have done the same it
works
> and the parts are cheaper. Great peice of mind for those hot
> days.......>>>>>.ANy Input??<<<<<<<<<