There have been reports of the GM stuff (OAT - Organic Acid Technology) turning to sludge in some vehicles. Has to do with the metallic components in the cooling system. Don't know what those might be. It's supposed to be good for 5 yrs/50,000 miles. The Ford/Chrysler stuff (HOAT - Hybrid Organic Acid Technology) is supposed to last for 10 years/150k miles. But those have some metal incompatibilities as well.
I have not used anything but the old green stuff (IAT - Inorganic Additive Technology) in my diesel, but it takes some supplemental anti-cavitation additive and occasional testing of that additive level. Newer diesels can use the HOAT coolant, with the longer life.
I suspect that in a stovebolt, that there aren't any whiz-bang materials that would prevent you from using the long life coolants.
[on edit] I'm wondering if there isn't a "Bob is the oil guy" style forum for coolants. That might shed some light on any potential incompatibilities of the various long-life coolants.
Last edited by klhansen; 07/04/2023 6:23 PM.
