One more question related to the cooling system. Ever since I found the build up under my radiator cap, I took it for a flush. The service manager said I can use G-05 and I followed his advice. Now I am wondering if I made a right decision.

1. Will G05 react with the residual dex-cool?
2. Are our GM cars compatible with G05.

Thanks for looking my post.

He obviously has no idea what he is talking about. Get that out of there. It is made for Ford and Chrysler vehicles. A simple Google search shows that: http://www.valvoline.com/pages/produ...asp?product=10

Get this in there ASAP.

Actually, the Prestone all makes, all models is G05 based. You should be fine.

I was going off of this info, (PDF) --> http://www.valvoline.com/zerex/pdf/Z...d=1B5D1AEA1AFC

The "problem" is not yours Haro...it'* the marketing gimmicks. The G05 coolant has been used in Europe, and several of the other imports manufacturers for some time. GM decided to go their own way with the Dex, while Ford and Chrysler held off a while and decided to go instead with the G05 based coolants. Then, through more testing, it was found that the G05 coolants mixed pretty well with Dex, and the old green stuff. It is still recommended to flush as much of the old stuff out before changing over. Since then, it'* been more marketing than anything else.

For a while, Valvoline Instant Oil Change was stocking just the G05 coolants to try and save money and stock space. After running into some problems with warranties (where the dealer would give people problems - mostly GM - with warranty claims if they ran the other coolants) they switched back to carrying Dex compatibles.

Thank archon and harofreak00 for your informative inputs.


I also educated myself a little bit on The Bob Is The Oil Guy forum. It looks like G05 actually safer to use if the cooling system is not air tight or topped off with other coolant. G05 also uses organic acid inhibitor technology(OAT) like Dex Cool, but G05'* OAT is compatible with inorganic silicate inhibitor which is used in traditional green coolant. It also seems G05 has a convincing record in the past decade. Please feel free to correct me if any of my understanding is not accurate.

Benn using the Prestone all makes for over a year now with no problems. I too had the gunk buildup under the cap with the Dexcool.