I decided to go with the G-05 based fluid, which has been used in Mercedes and Volkswagen for years, and more recently in most DaimlerChryslers, and Fords. It is supposedly compatible with traditional green stuff, which the GM-dexcool definitely isn’t. I based my decision on two excellent articles published this year in Car&Driver by Patrick Bedard. Patrick Bedard is a Hemi nut concerned with protecting his old cars. He did some serious research, including interviews with chemists from major coolant manufacturers and concluded that older cars should stick with the green stuff or this new G-05 stuff. Apparently the GM Dexcool is very aggressive and only works in cars designed specifically for this coolant as it may damage gaskets, seals and corrode metal not alloyed specifically to handle Dexcool. The G-05 coolant on the other hand, is supposed to have better anti corrosion characteristics than the green stuff, yet be gentle enough for our keepers. Patrick also mentioned the other new stuff used in heavy duty trucks, which can last up to 300,000 miles. However, he thought that might also be to hard on old cooling systems. Zerex sells the G-05 stuff and Ford sells it as “premium gold coolant”. I started using it in May and it seems similar to the green stuff, except for a urine-like color and slight chlorine odor. Anyway, after reading the article I felt confident in the G-05 stuff. I’m not sure what months the articles were published, perhaps May and June, 2002.