I saw some Rotella T straight weight SAE 40 today at TSC and got to wondering if that would be a good choice for my older Stern drive.
it is a 1988 chevy based 4.3, OMC Cobra stern drive. Carb'd if that makes a difference.
the maintenance manual i bought says not to use multi-grade oils, presumably because multigrades of the day were more likely to shear under sustained high rpm use (not that it revs all that high, 4,600 rpm max).
i know lots of people are using 15w40, and that would be fine for me too. but i saw the SAE 40 and it looks like it might be worth considering.
as i understand it, the 25w40 they sell at the marina is basically a straight 40wt with a "w" rating, that is to say that most 40wts will pass a 25w rating as well.
thoughts?
it is a 1988 chevy based 4.3, OMC Cobra stern drive. Carb'd if that makes a difference.
the maintenance manual i bought says not to use multi-grade oils, presumably because multigrades of the day were more likely to shear under sustained high rpm use (not that it revs all that high, 4,600 rpm max).
i know lots of people are using 15w40, and that would be fine for me too. but i saw the SAE 40 and it looks like it might be worth considering.
as i understand it, the 25w40 they sell at the marina is basically a straight 40wt with a "w" rating, that is to say that most 40wts will pass a 25w rating as well.
thoughts?