I normally run 10W 30 but I just bought a Mobil one fill cap and it says 5W 30 on it. WHat are you guys running?

 

castrol syntec, 0w-30

 

5w-30
if i could find 0w-30 mobil I would run that..

If it gets cold where you are at, i would keep the 10w for winter and 5 for summer..

 

keep the 5 for winter and 10 for summer.

 

why 0-w-30 oil?...i run 5/w/30.....in the summer, dont drive it in the winter

 

5w-30 Valvoline.

 

An oil guru on this board and ls1tech, patman, actually runs used oil analysis tests and thinks the 30 weight M1s are too thin for best protection, show higher wear #s than his favorite, German Castrol. I like to use M1 5w-40, an oil that has gotten excellent scores on tests. But only because I can't find the GC in my area.

So why would GM recommend the thinner M1, maybe for gas mileage, don't know. All M1 synths are good oils, no doubt, but the oil tests I've read on the boards, especially BITOG, are convincing.

 

Actually, 5 for the winter and 10 for the summer.

5 is thinner. So when oil is cold it will move slower. 5 will get to the engine from the pan quicker than 10 will. That is why you use 5 in the winter. If you read your manual, it says you can run 10 if the weather never gets below X degree (I cant find the exact number right now).

 

Mobil 1 Synthetic 5w-30