Import Service:  Sept 1995.

DEALER DIRECT (a monthly feature of dealer service bulletins)

to quote:

"Mazda does not recommend the use of propylene glycol coolants in 
Mazda vehicles.  According to Mazda, available information indicates 
the following characteristcs regarding prpylene glycol coolants:

- They provide less heat transfer.
- They may not provide adequate corrosion protection (to meet Mazda's 
specifications.)
- Freezing temperature of these coolants is 10-20 percent higher than 
ethylene glycol-based coolants. 

For these reasons, Mazda recommends the use of an ethylene glycol and 
water mixture in the cooling systems of all Mazda vehicles."

-dan