iamdub
Full Access Member
Dex-Cool is just fine as long as the system doesn't have any leaks. If the coolant level isn't completely full, that extra space is replaced by air and air is what lets some of the components in Dex-Cool evaporate, leaving that muddy residue behind. So, on an older car that's more prone to developing a leak somewhere, flushing the hell out of it and using the regular stuff is probably the safer bet.
I don't know for sure if the Prestone equivalent is the same formulation as Dex-Cool, but it's never given me any problems. Once everything is flushed out very well, you could use whatever coolant makes you feel warm and fuzzy inside. I've always considered going with the "green stuff" and I'm sure it would've been perfectly fine. But I end up with the "orange stuff" because it just looks right in a GM.
I don't know for sure if the Prestone equivalent is the same formulation as Dex-Cool, but it's never given me any problems. Once everything is flushed out very well, you could use whatever coolant makes you feel warm and fuzzy inside. I've always considered going with the "green stuff" and I'm sure it would've been perfectly fine. But I end up with the "orange stuff" because it just looks right in a GM.