A common misconception seems to be that this coolant will not mix with other
coolants. Every time I have gone to my FLAPS to buy a gallon, I get the same
dissertation - so I called the 800 number on the side of the bottle. They
told me that that was a bunch of BS. They said it would mix with ANY ethylene
glycol based fluid. Now, I know I'm opening myself up for flaming here - but
that's what they told me. Regardless, why would you need to mix it anyway? If
one flushes the system - it's not an issue. I use Prestone 5/150, and it
seems to work just fine.

My two cents !