Wally

iTrader: (1)

I never quite understood why boats don't just use a straight 50 weight oil and be done with it. The 20 in the 20W-50 is for winter weight...i don't know of anyone running their boats in cold weather! I mean iv'e boated in low 60's in the early Fall but that's about it. I always used a straight 50 weight oil in my boats

Mariah212Z

I believe there is an advantage of a multi weight oil (15/40, 15/50) under a dry start (after sitting for a while) and the lower number to quickly lubricate and as the oil heats provides the higher viscosity.

IMO

SB

iTrader: (1)

Heh, Do people with stroker motors use stroker oil ?

bajaman

what exactly does ambient air temperature have to do with anything? Your oil temp whilst operating will be the same whether it is 10 degrees outside or 110 degrees...?

But for God's sake never use Puke-oil...er, Penzoil if you want ANY sort of engine life!

j272

what wrong with penzoil?

j272

In a multi vis oil, the low number is for the low temp. the high number is for higher operating temperature. if you run straight oil like 50 weight when the motor is cold it takes quite a while for the oil to flow/reach operating temp like 150+ degrees F. thats when it will provide proper lubrication, so I assume we would be cause premature wear if we start a cold motor(say65*F) on straight 50w.
prob be ok if its 100*F. out.

Robert Dunsmore

you don't live in Arizona we boat all year boat never rests here!! even in winter we dont go below 60....

Robert Dunsmore

In Arizona the difference when water temp is 90 degrees, so when your engine is cooled by lake water, definitely makes difference. Compare to 89 outside and lake water is 68. You bet it makes a difference when you live in a state where your Max temp is 88ﾟ in the summer. Or here when it's 115 out and lake water is 90+ , but what do I know , ask my wife not ****!

AmiableDave

If you're running the proper thermostat and your cooling system is operating properly. What difference does the ambient temperature and oil have to do with anything?