Originally Posted By: Donald
From Zerex:
The Zerex G05 formulation is 100% compatible with the conventional green coolant product. You may mix the two or flush the entire system with the G05 with absolutely no problems existing.
Does everyone agree?
Can I assume any G-05, not just Zerex?
X2 on the comment that if you don't COMPLETELY flush the system, you should follow the maintenance schedule for conventional coolant (personally, I do anyway- 5 years seems like WAY too long to run any fluid).
AFAIK, all G-05s are essentially the same (except for some reason, Ma Mopar dyes hers red when everyone else uses pale yellow). Zerex is certainly the most readily available unless you make a trip to a Ford or Mopar dealer.
FWIW, been using G-05 in my 66 Mopar 440 ever since the rebuild 3 years/27,000 miles ago. I popped a new thermostat in a few months back, and everything in there looked absolutely great. I know the HOAT coolants are primarily to protect aluminum and there is ZERO aluminum (well, the tiny little water pump flange...) in the 440 itself. But with a new aluminum radiator, it seemed like the way to go and I have to say so far so good.