Hi all... Not a Crossfire owner yet but I hope to have a Red coupe within a few months.

A friend of mine works for Phillips oil and he said MMO is very similar to ATF but it has a bit of Wintergreen oil in it to make it "different".

It does help clean out engines before oil changes but be careful because "Varnish" is not an enemy of engines... It actually prevents corrosion on internal steel parts. For each gallon of fuel burned, your engine must get rid of a gallon of liquid. Most goes out the tailpipe, but some goes into the engine with blow-by. As long as you get the oil temp above 212 degrees (it does in certain parts of the engine), water will boil out.

Use in the fuel does help provide some lubrication to the upper cyl walls where the rings provide alot of force and the oil film gets thin.

Another advantage is the heavier oil does help knock carbon loose from the combustion chambers.

I'll sure have to try it in my wife's Impala... It needs better gas mileage.