I've been using Texaco's Havoline coolant for over a year. I mixed it
with the Autobahn coolant that was in all three of my Vanagons and the
Audi. So far, no problems. Last time I looked for coolant, I was worried
that there was some "real" reason for not mixing Havoline with any other
kind of coolant (I figured the reason for the warning was to get you to
buy and use only Havoline), so reading the label on the Havoline, I see
that the warning about mixing is no longer on the bottle. I'll let you
know if anything happens, but after a year, I can't see anything
happening that wouldn't happen anyway.

Steve and Jo Ann Wacker
San Marcos, Ca.
90 Carat
86 Syncro x two
86 Audi 5000 CS Quattro