David!

Is that a real question?
If yes then my answer is: depends on the temperature!

If you are looking at your sandwich cooler application then mount the oil 
cooler separate or after the air cooler. It is just physics. The intake air 
will heat quicker than the oil but not become as hot. Therefore you lose 
some cooling of the oil on hot days but not all of it. Reverse it and you 
would lose all cooling of the intake air. The activation temperature of 
thermostatically controlled fans on intercoolers is usually 70 C.

This would have been a perfect question for the TDI-conversion list at 
Yahoo.com.

At 09:20 AM 11/25/02 -0500, you wrote:
>Date:    Sun, 24 Nov 2002 21:55:46 -0800
>From:    David Marshall <vanagon@VOLKSWAGEN.ORG>
>Subject: Attention TDI Gurus!  What is hotter, oil or compressed air?
>
>I am doing the final - on paper design of my ALH TDI installation that will
>be going into my Syncro DoKa over the winter.  From what I have heard from a
>lot of TD and TDI owners and from my personal experience with a 1.9L AAZ
>Turbo Diesel is the oil temps can get damn hot with the turbo working all
>the time.

snip ....

>So in making the cooler sandwich, which one should be on top - the air or
>oil cooler?
>
>David Marshall
>
>Fast Forward Automotive Inc.
>4356 Quesnel Hixon Road
>Quesnel BC Canada  V2J 6Z3

Bj�rn Ratjen
Mill Bay, B.C.

1987 Vanagon Syncro est alia (self camperized, TDI )
1978 VW Bulli (self camperized)
1995 Passat TD Wagon (hers)
1970 VW Beetle (now mine)
1991 Jetta TD (now son's)
1986 Jetta TD (daughter's)
1986 Jetta TD (mine)
1982 Westy Vanagon Diesel (son's)