best type of oil

[HB.FAB.CO]

what is the best oil to use in a 99 22i w/ merc 350 mag mpi

[TeamAllen]

I'm pretty sure my Merc manual recommends straight 40W. Their website pushes "Mercury Precision 4-Cycle 25W-40 Marine Engine Oil". I use Castrol 40W from Pep Boys. Check Merc's link below to fuel and oil FAQ.

Mercruiser FAQ (http://www.mercruiser.com/fueloil_recommendation_faqs)

Some guys use synthetic. That Merc link strongly recommends NOT to use it. There is also another previos thread on this topic here (http://www.tigeowners.com/forum/showthread.php?s=&threadid=952&highlight=oil)

[maroco]

Would that be the same for the 21v 2001 350 ? would it be a straight 40w marine oil as well ?

[GIZMO]

I called Merc. and asked about synthetic oil, The guy said they dont recomend it only because they have not tested with it. He did say that they were comming out with there own brand of synthetic oil. Im sure its just a big name oil put into a Merc. bottle.

I use Mobil one.

[teachercop]

Mobile 1,,,in my 99 2200i,,,315 MPI
seems hard to beat the synthetics....
Talked to MerCruiser Tech's also,,their primary point was they want the engined adequately warmed up before you start pulling....

[GIZMO]

Intresting point, When I shopping for a boat MasterCraft offered me 10Year (not sure on years, might have been more) engine warranty but it was only valid if you used mobil one.