oil for 87 prostar
 

I have been using rotella t for the 2 years I have owned the boat, but I remember reading somewhere that they stopped putting in an additive that is needed for the flat tappet cam in my engine. Im not entirely sure if this is true, but what engine oil would be best for my engine? 351 indmar, non powerslot
thanks

If you want to stick to a multi, Valvoline VR1 20W-50 seems to be the current best choice. It has the high level of ZDDP you need for the flat tappet engine. The Rotella still has the ZDDP in the straight 30 and 40 weights as well. For a very complete discussion, check out CorrectCraftFan.com and do a search for either the VR1, Rotella or ZDDP oil.....lots of tech talk over there.

I'm close to your latitude and run the 20W50 VR1. But given our temperatures in Texas, you'd probably be fine with the straight 40 as well.

I've always run Valvoline VR1 40 weight in our '89,
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Stupid question but what is the difference between the straight 40wt and the 20w 50 VR1?

I'm not an oil expert, but the the multiweight oils are going to help you with lubrication at startup. Whether or not you can get away with using straight 40W oil is going to depend on how cold it gets when and where you're operating.

Thanks for the clarity. I better use the vr1 20w 50 here in the midwest.

thanks for all the replys. I went ahead an bought some vr1 20w50 at autozone.

Oil for 1995 prostar 190 South Florida Boat
 

Please tell me what oil is the best to use in this boat with a chevy engine?
thanks for your time, and how many quarts do i need ? 6?

5 qts (if you get it all out. I'm alwyas a little shy of 5 qts to get it full even after running the engine for a few seconds).
Any oil suitable for your car will work fine. I've run 10W40 before, but typically stick to 15w40 since I buy it by the case(s) for my diesel pickup anyway.
15W40 is reccomended by Indmar.
I use either Rotella or Delo as that's what's usually on sale.