Geny Oil Viscosity?

[Sadey]

Changing the oils for the first time on all power plants. For the Onans 20KW and 8KW the manufacturer's recommendation is different from Hatteras's of a straight 40w. I'm using Shell T1 40W for both DDs. Can/should I use the same or pick the temp rating recommendation from Onan and use that?

[Pascal]

I ve used Rotella 15W40 in just about every generator I ve owned or used incl Norpro Isuzu, Westerbeke, Northern light and Ohnos

[jmooney]

Same, Rotella 15W40 , I use it in my truck and tractor too. I use Mobil Delvac 2 cycle 40w in the main engines.Sold as MTU Power Guard for 2 cycle engines.

[Pascal]

Don’t buy it at West though. Shop around, usually Advanced Auto parts or NAPA has good prices on it

[Passages]

For my ONAN 20 & 5kw genny's, I use Delo 400, 15-40w, rated CK-4.

Picked it up at West Marine 2 weeks ago for $14.99/gallon.

[SEVEN]

X2 on the Delo.

[Boatsb]

Check it calls for a higher zinc. I use valvoline blue premium 15w40 on my cummins engines.

[racclarkson@gmail.com]

The best stuff to use in gennies wasn’t invented when Hatteras printed (or typed in my case) your manual.

[Sadey]

When I talked to the Onan parts distributor, they said 15W40. So that’s what I will use. Just wanted to bounce it off you guys to see if there was a match.

[Hat52MY]

I use Straight 30.... below is a screen shot of the oil recommendations from my Onan MDL Manual with the various recommendations based on environmental temperatures where the generator lives...

EDIT: Not sure how clear the attached image is to read. The “Oil Recommendation: Recommended engine oil viscosities are 15W-40, 30, 2OW-20, and 1OW meeting the American Petroleum In- stitute (API) classification CD/SG, CD/SF, or Military SpecificationMlL-L-2104C. Whena5W-20or5W-30oil is required, it must be a synthetic oil meeting Military Specification MIL-L-46167, MIL-L-2104C, or MIL-L-46152B. Viscosity 5W-20 and 5W-30 mineral base oils are not recommendedfor use in the engine un- der any condition.”