Synthetic or Petroleum?

[AmericanPride]

Can someone tell me if Synthetic Oil is ok in a 1991 OMC Cobra 5.7 (Chevy 350) Crankcase? 10W-40, 20W-50? And, How about Synthetic Lower unit Oils and Greases? I am in SE Texas where it's Hot. Synthetics seem to take the heat better. Thanks,

 

[Bondo]

Re: Synthetic or Petroleum?

Synthetic Oil ,+ Synthetic Lower unit Oil is All I use....

 

[bowhuntrrl]

Re: Synthetic or Petroleum?

Bondo, Are you running a Mercruiser?? Reason I ask is I just had my Alpha remanufactured and they offer a 2 year warranty, BUT NOT if you use synthetic gear lubricant. They claim to have seen strange failures due to synthetic lube with a Mercruiser. I run good old 80-90 W hypoid in mine.<br /><br />bowhuntr

 

[magster65]

Re: Synthetic or Petroleum?

I stop for coffee at some of the local shops, one mechanic stated to only use merc. oils. The synthetics work too well in some cases causing roller bearings to slip instead of roll.

 

[horndog]

Re: Synthetic or Petroleum?

what about synthetics for engine oil?

 

[AmericanPride]

Re: Synthetic or Petroleum?

Bondo, Which synthetic oil do you use in your crankcase? Mobil 1, etc....<br />Thanks,<br />Dennis