I guess the answer is "depends"

It's been a long time
since I have driven a wasserboxer and really i have never paid attention
to the oil temperatures.

One has to realize that the OE cooler
isn't really a cooler, rather it is an oil temperature regulator.�
The fact that coolant is used, it try to keep the oil at 95C or so which
is the engine's coolant temperature.� This is useful as it brings the
oil up to temperature faster which is a useful thing.

If I was
going to add an oil cooler I would ensure that the adapter has an
thermostat that opens only when the oil temperature is greater than circa
90C so that it will warm up as fast as the engine engineers wanted it
to.� Really want you want to do is remove the extreme high
temperatures obtained when you are really working the engine.� 

In most cases you want the oil to be at coolant temperature or
slightly above so that condensation will come out of it.� Most modern
synthetic oils will survive quite high temperatures.

David
Marshall
VW Adventure Driver and BMW Adventure Rider
 
http://www.hasenwerk.ca

On Mon, October 19, 2009 22:42, David
Cohen wrote:
> Hi,
>   I was wondering if an external oil
cooler, bigger than the stock  one,
> is
> good for
extending the life of a stock 2.1 motor in a 1990  Vanagon?
> 
> Thanks,
> David
>