15W-40??? Isn't that problematic in DD 8-71s?

[jim rosenthal]

DDs have always used straight weight oils as noted above. I wonder how many damaged DD engines are alumni of that yard. Hopefully not yours.

I ran Rotella 15-40 in my Cummins four-strokes, until I switched to Mobilgard SHC1. I still run Rotella 15-40 in my two diesel cars. But I would never put it into a Detroit.

[SKYCHENEY]

https://www.samsmarine.com/Manuals/Delo%20400.pdf

[Captain Ralph]

There filters are also pretty good,

Made by Wix Filter corp.

[Photolomy]

I've always used the Napa 40wt, but I have seen arguments that 40-15 is ok, and to be honest, they seem convincing. I don't use it because 40wt is cheap enough and available enough that it isn't worth it. And I am not trying to start my motors in the Arctic.

[Captain Ralph]

There is a reason the Detroit factory included this in there 2 stroke manuals.

[Captain Ralph]

I've always used the Napa 40wt, but I have seen arguments that 40-15 is ok, and to be honest, they seem convincing. I don't use it because 40wt is cheap enough and available enough that it isn't worth it. And I am not trying to start my motors in the Arctic.

In the Arctic, lighter oil is available. The CF-2 rating MUST still be achieved.
Oh, Only in single weight oil.