PatriYacht

15-50 Mobil 1 is popular with the hi perf. crowd. Remember, your boat will never see a below freezing start up but it will see heavy loads continuously.

Back4More

NAPA 15w-40 for low performance and Kendall 20w-50 for high performance.

ezstriper

speaking of mobile 1 20w 50 cannot find it around here...been running the 15w 40 anybody know where the 50 can be found ? thanks Rob

Knot 4 Me

Never heard of Mobil 1 20W50 or 15W40. Only 15W50 which is what I run religiously.

As for the 4.3L, Merc 25W40 (which is a blended, not a multi-viscosity oil), Mobil 1 15W50, any good 15W40 or 20W50, straight 40W (if you don't run in temps below 60 degrees). The local marinas here put NAPA or Chevron 30W in every boat they winterize unless the owners specify a different oil.

caseypierson

thank you all so much for your time

Fixxxer22

20w-50 brad penn. just my 2c.

minxguy

You wonder why there is so much confusion on oils.

A 25w40 IS A MULTI-VISCOSITY!!!!!!!

Who told you that an XX w XX oil IS NOT MULTI-VISCOSITY?

It has no bearing on the viscosity whether the oil is blended or not.

And the oils you suggested...guess what, ALL MULTI-VISCOSITY.

Ken

minxguy

15w50, which by the way is a multi-viscosity oil just like the 20w50.

Ken

Irishtornado

15w40

VillainIII

I run straight 40w. I remember Bob Teague recommending straight weight oils in a tech column a few years back. IIRC, it had something to do with multi-grades not handling moisture as well as straight grades, and who starts there engines and just takes off with them cold anyway?