Oil for Inboard motors

[AFDan52]

I am going to be changing the Motor oil in my In-Board soon and wanted to get everyone's opinion about the best oil to use, I'm starting my maintenance program this weekend and want to get things ready right away. What do you use?101smily101

 

[SuperD]

Whatever brand you decide to use, use a slightly higher viscosity than what might be recommended if the engine is a little older. The oil companies used to manufacture their oil in the mid range acceptible for a given viscosity spec but now due to pressure for higher gas mileage, have started manufacturing them at the very bottom of the limits.

 

[SuperD]

Consulting an oil expert on another site, here are some recommendations:
Mobil M1-EP
Mobil Synthetic Truck & SUV
Any diesel engine recommended oils

These oils tend to have more anti wear and anti corrosion additives than typical automotive oils.

 

[Silver Streak]

I run a good diesel oil in my inboard Kodiac Chevy Vortec engine. Remember, these marineized engines run for longer times at higher rpm's than what they were sort of originally built for...

 

[stratofisher]

I have been running straight 30W per the manual, but have recently starting using 15 W 45 Rotella diesel oil. Seems to work fine, and is easy to find.

 

[Bduck]

Rotella is a very good brand and is now carried in WalMart in a gallon container. The manufacturing of oils has changed dramatically. Synthetics are very good with very low to no friction. The oil to gas ratio, using synthetic oil in 2strokes have change quite a bit in older units with the less oil burn type smoke you see on the lakes coming from these type of engines. Improved engine performance follows.