i bought a fountain with twin 454's the guy has no clue what he used because he never changes the oil. What does this probably have in it or should have it in it?

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.

ok ive heard 15-40 as well. The boat is great and guy always had service done on it, but kind of one those people that has no clue about the mechanics of things, just pays for it to get done.

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

Ok were on two different numbers now, not so considered with brand more of less weight. Anybody know what the manufacture reccomends for a 454 MAG

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

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.

thank you all so much for your time

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

if 20-50 isnt available what is the next best choice