motor oil

[old jim]

My 2003 40 horse 4 stroke EFI OB has as it's top API oil rating as SF. I beleive the current
API top rating is SN. Can I use this oil in my OB?? Thanks, old jim

 

[Chris1956]

Re: motor oil

Jim, every year of so the oil designation changes. Newer oils are better than old oil, but are "backward compatable",

On that outboard, Merc should call for a FC-W designation. That is a special four cycle marine engine designation. I would recommend you check it out and use the right stuff.

 

[old jim]

Re: motor oil

Chris, the owners manual says, Api ratings, SH, SG, SF,CF4, CE, CD, CDII. I could not find an API rating on
the Mercury oil containers. I am seriusly considering using Casterol products next season as I have completed
this years service of the motor. old jim

 

[Chris1956]

Re: motor oil

Well. maybe it likes the auto stuff, but that would be surprizing. Did you check the rating on the Quicksilver 25-40 oil? That used to be all Merc offered, for Mercruiser sterndrives.