Oil

[larryman98]

Hi guy's. I have a question about my 3.7 Mercruiser in my 1989 21' Galaxy Magna,cuddy walk around.

My 1989 3.7 Mercruiser has great oil pressure at start 60-65 psi. After about 30 minutes of 3400,3450 rpms, the oil pressure drops to approximately 5psi or so when returned to idle.
I am using straight 30 HD oil. Is this there another type or brand of oil that would remain thicker when hot?

I love the power and efficiency of this motor and want to keep it in good shape as long as i can.

Thanks guy's.

 

[Don S]

Re: Oil

Nothing wrong with the straight weight oil, here is the weight vs air temp chart from Mercruier

 

[90stingray]

Re: Oil

You could run some 20w50. But I think you are in spec with the 5psi.

 

[Lyle29464]

Re: Oil

oil also transfers heat. Take it easy when you think about buying thicker stuff.