F1Addict

Should I be using orange (Dex-cool) or green coolant in my '89 Renix?

Radi

Green. The old fashioned Ethylene Glycol stuff. The HOAT would probably be OK too. Not the OAT (Dexcool).

belvedere

Use the traditional green. Like Radi said HOAT is OK, too, but HOAT is G-05 (Mopar, Ford, or Zerex). The vast majority of universal coolant are OAT (Dexclones).

Bbasso

the Orange stuff needs distilled water only can't use anything else or it turns to crap but works well when done right.
But I'd never use it.

Radi

Thanks! I edited out the "universal" comment in my post for that reason. You had it right (OAT) and I had the Universal wrong (HOAT).

belvedere

Yeah, I sure wouldn't hesitate to use the HOAT. If you don't mind the cost, you could extend your coolant change intervals.

F1Addict

Cool, thanks. I used Zerex G05 (flushed and filled a couple months ago) but I need to replace my pressure bottle and wondered if I should be using that stuff. I'll flush it again and fill'er up with the green stuff when I swap the bottles.