What Oil do you use?

[Tru2Chevy]

10-30 or 10-40 Mobil1, depending on the season.

 

- Justin

[cutlass1991]

Castrol GTX

[pitzel]

A cab company I am familiar with runs the GM 3.1L V6 out to approximately 40k miles on a single oil change with a good synthetic. He uses Used Oil Analysis, and has experienced no detectable excessive wear or sludge contamination resulting from the use of a long interval.

 

My 3.1 manual recommends filter changes every 15k miles. Even with a synthetic running for long drains, there isn't any reason to change the filter prematurely.

 

If one's in Canada, Imperial Oil/Esso/ExxonMobil XD-3 Extra 0W-30 is very excellent stuff for the 3.1's, and dirt cheap too for a full syn.