Originally Posted By: Ramblejam
Originally Posted By: Bluestream
I would not use 5W30 in a marine engine at any time. These engines run very hot oil temps, and a 5W30 will shear down in no time. Might be okay if you only put 10 hours on it.
the 15W40 is fine for any temps you will be using.
Cool story, bro.
Tell me now -- just what oil temperatures do you expect to see in a raw-water cooled, 140°F thermostat, recreational sterndrive in
Seeing how the recommended oil is 20w40, it'd be silly to suggest anything with a much lower winter weight than that.
Our boat has the 5.0 Mercruiser. It is the little brother to the 5.7.. Same HP.. just a physically smaller and lighter engine. She's fuel injected too.
Hopefully the beast will get taken out of her cave this weekend. It has an oil temp gauge on it and ill get some numbers for you.