oil grade

[nmu98]

Originally Posted by IRA51

i HAVE USED 10/40 IN MY 2000 Z28 with a 382 stroker motor motor (LS1) 450 hp at the rear wheels (11.86) in the 1/4 mile and street driver in Phoenix for 6 years with no problem 26000 miles and runs like a champ .

OK, but that is not a 6.0 in a Hummer, and has WAY more HP... You would want the higher wieght oil for less shear in that engine....

I am not saying I know right or wrong here... I am just sharing my idea.....