Hey, i just took out the 10W30 from my 97 Z28 M6 and it was running like water, no wonder i had such crappy oil PSI. I got some Mobile1 SuperSyn 15W50 "made for performace vehicles" I just wanted to make sure before i put it in that it would be what i'm looking for ( i drive my car hard in hot whether). I also got a FRAM oil filter.

 

I run 15w50 in the summer and 5w30 in the winter..... No probs here.....

 

If your engine is basically stock internals, the only reason you would need 15W-50 to keep the pressure up to "normal" would be in the case of serious internal wear. What were the numbers you are referring to as "crappy oil pressure"?

You might want to to do a search for posts by "Patman".... a lot of first hand data on test results for a variety of oils. He has found a German-made Castrol 0W-30 synthetic that tends to be slightly thicker than the Mobil 1 5W-30, and produced better result (based on oil analysis) in his car.

You also might want to do a search on "Fram".... I think most people, and several respected comparison tests have found them to be one of the poorer made and poorer performing filters. AC/Delco, Mobil 1, WIX, etc. are all better filters.

 

I changed to m1 15w50 and love it! it seems to run better..but that might just be in my head.lol