Proper oil

[onion]

I have a 1982 Starcraft with a mercruiser 120 4 cyl gm engine. The plate on the engine says to use SAE 30 oil. Does that mean I can use 5W or 10W 30 oil? Advice is appreciated.

Sent from my iPhone using Lake Ontario United

[GAMBLER]

Use straight 30 weight oil. They sell it at any auto parts store.

[onion]

Thanks

Sent from my iPhone using Lake Ontario United

[fisherdude1]

I bought a 88 Crestliner with a 4.3 in it and went through the same thing. As SAE is no longer a rating they use. Plus new engines have different cam shafts and lifters and use different oils. I ended up with 15W40 Rotella oil in mine. As Mine said 10w for cold weather 20w for reg temps amd 30 for hot weather. Been very pleased with how it's worked.

[jimski2]

Boats are rarely used in below zero temperatures around here so that is why 30 weight oil is advised. For fuel mileage the newer synthetic blends work better but the thermostats in your boats engine do not reach over 200 degrees F which is what the newer oils are designed for.