oil type

[jwkoehn]

96 gm 383 stroker

looking to get some opinions about using shell rotella oil 15w4o Based on the info I have it appears to be a good oil for a hard working marine engine any thoughts

 

[wire2]

Re: oil type

The 15W is the cold viscosity rating, why would you need it if not operating at near or below freezing?
I'm of the impression that plain 30 is the most appropriate, 40 if you feel something a bit thicker is warranted.

As I recall, 30 was recommended when I got my OMC 5.7 new.

 

[180shabah]

Re: oil type

Great another oil thread, how long will this one get???

Bottom line, changing the oil regularly and using a HIGH FLOW oil filter will prove more important than you choice of oil. I agree that a 15W base oil is probably a little thin for a boat but if you let it warm up you'll be fine.

Be prepared, you are about to get more conflicting responses than you can handle.....

 

[HT32BSX115]

Re: oil type

Mercury recommends 25W40 nowadays.

If you leave the boat in the water all year it's a probably a good idea to use an NMMA FC-W type oil like Mercury's 25W40.

Read the following info:

http://www.nmma.org/certification/programs/oils/fc-w.asp

If you ask here on this and other sites you will get a lot of emotional responses. Oil is emotional.....sort of like Ford and Chevy. Or Mercury and Volvo etc...




If you have a lot of 15W40 around because you have a diesel. It will work just fine.

Just change it prior to 100 hrs and/or at the end of the season, if you store your boat for months at a time after summer.


I use Shell Rotella 15W40 in everything I own...(except for the airplane... that gets Aeroshell 100) I also ran it in my 1966 Mark Twain 150 Mercruiser .....I guess it didn't hurt it....it was only 38 years old and still running well when I sold it.


Cheers,


Rick

96 gm 383 stroker

looking to get some opinions about using shell rotella oil 15w4o Based on the info I have it appears to be a good oil for a hard working marine engine any thoughts