Evans Coolant - S4 Back in Service

[Lawrence Bardfeld <LB6116@PITCAIRN.com>]

Just in time for the new snow here (Philly), I've got my car back, the 
Evans coolant flushed out and replaced by conventional water-based 
coolant.  My mechanic, who had previously used Evans successfully in a 
variety of Audis, thinks that perhaps due to its higher viscosity and 
the S4's cooling system the two were just incompatible (resulting in 
my 2 turbo coolant pump meltdowns in 2 days).  My question: what might 
be different (thinner tubing?) in the cooling system of a car such as 
mine ('93 S4) that might account for the difference (compared, e.g., 
to a 5000)?

And a merry Christmas (and thanks) to all!
Larry Bardfeld