In a message dated 96-07-17 03:57:16 EDT, most@gibbs.oit.unc.edu (David E
Most) writes:

<< 
 2) The only phosphate free coolant (NON-vw) near me is a brand call 
 Sierra.  Is this acceptable for VWs AND if so, can it be mixed with the 
 Autobahn brand?
  >>
Sierra is based on propylene Glycol instead of ethylene glycol.  It's major
advantage is that it is non-toxic.  I do not know of any problems with using
it except I believe it should not be mixed.  Both prestone and Zerex sell non
phospate antifreeze.  It is marketed as that long life stuff at about $10.00
a gallon.  This is my preference.

Dennis.