Coolant

[Guest]

I have a 91 Coupe. I read somewhere in this column that there is a special antifreeze to use in the Reatta/3800 engine. Please advise.

[sahein]

GM has changed its recomended anti-freeze. They no longer recomend the green stuff which needs changed every year. They recomend Dex-cool which is orange and has a five year life in your engine and provides better metal and heat protection.<P> <BR>Prestone® Extended Life 5/150 Antifreeze/Coolant is recommended and formulated for use in all GM vehicles that require DEX-COOL®* coolant, as well as all other cars and light duty trucks with aluminum radiators. This patented formula has a concentrated blend of premium long-lasting inhibitors for extended performance, protecting against temperature extremes and the ravages of rust and corrosion. Prestone Extended Life 5/150 Antifreeze has been approved by General Motors to be licensed as a DEX-COOL® product under the GM 6277M specification, and will provide the following key benefits:<P>Unsurpassed freeze-up and boilover protection <BR>Meets or exceeds all ASTM and SAE standards for coolant corrosion protection <BR>GM DEX-COOL® approved <BR>Compatible with other DEX-COOL® approved coolants <BR>Meets Ford WSS-M97B44-D, and property and performance specification requirements of DaimlerChrysler MS-7170, MS-9769 <BR>Use a mix of 50% to 70% Prestone Extended Life 5/150 Antifreeze/Coolant and water. Optimum change interval - every five years or 150,000 miles. <P>* DEX-COOL® is a registered trademark of General Motors Corporation.

[Guest]

The DexCool formula used for current GM factory fill is Texaco Havoline. If Prestone is certified as DexCool it must be a recent development. <P> If changing from green to orange, flush, flush, flush, the system first. Any remnants of the old coolant in the system pretty much negates the benefits of the new technology.