Rotella oil in Onan Generator?

[Goodspike]

It could be worse. You could own one of the new 3.0 Duramax GM engines. Here's the complete list of oils that meet manufacturer specifications!

https://www.gmdexos.com/brands/dexosd/index.html

[dkoldman]

Originally Posted by Goodspike

It could be worse. You could own one of the new 3.0 Duramax GM engines. Here's the complete list of oils that meet manufacturer specifications!

https://www.gmdexos.com/brands/dexosd/index.html

Ha Ha

[dkoldman]

Ok folks, as the OP, I get to layout how I concluded this topic.

Remember I am a person with ZERO experience changing any oil in a RV Generator. But, I do have a 9 year old Chinese made Sinemate 2500 Portable Generator that I will go toe to toe with ANY Honda owner. The key to generators is keeping carburetors clean and a good oil changed often .

Here is how I concluded.

While the Rotella 15w -40 will work and most will never see any issues, it was clear to me it did not have any gasoline API specifications

Since I was determined to find a oil that 15w -40 to support ambient temperatures to 100F, the 30 weight oil options were excluded.

Since Synthetics were not recommended by Cummins Onan and due to the fact that they cost more, all Synthetic options were excluded.

Since all 15w -40 oils are compatible with Diesel engines, I only viewed options that were compatible with Diesel & Gasoline. Gasoline API specification is SN

I was left with only 3 options.

1. OnaMax 15w -40 as it is OEM, but at $17/quart I did not wish to support their complex scheme to rip off customers trying to do the right thing or simply don't know any better.
2. Wal Mart's Super Tech 15w - 40 it is by far the cheapest, but something about putting Super Tech in my 5500 did not resonate.
3. Chevron Delo 400 15w -40 it came at a very economical price, rated for Diesel & Gasoline, Chevron brand name and the SN API Specification.

So I have picked up a gallon of the Chevron Delo 400 15w -40 and intend to change the oil this weekend when I receive my Onan Oil Filter.

[NXR]

Where did you find that the Chevron Delo 400 15w-40 is good for gasoline engines? Chevron seems to make different variants like SDE, MGX and XLE and none of the ones I found mentioned gasoline. What specific variant did you decide to go with?

Ray

[NXR]

Interesting. Cummins sells OnaMax for far less than others, $6.36 a quart.

https://shopcummins.com/products/cum...31272009826404

With shipping for 6 quarts and tax it came to $9.67 per quart. I didn't feel like driving sixty miles round trip to the nearest Cummins store and that would have cost me $8 in gas anyway. Shipping was $15, or $7 to my way of rationalizing my laziness.

Ray

[dkoldman]

Originally Posted by NXR

Where did you find that the Chevron Delo 400 15w-40 is good for gasoline engines? Chevron seems to make different variants like SDE, MGX and XLE and none of the ones I found mentioned gasoline. What specific variant did you decide to go with?

Ray

Wal - Mart and Chevron site The API SN Specification is for Gasoline engines.

Delo 400 SDE SAE 15W 40 with ISOSYN Advanced Technology is a mixed fleet motor oil recommended for naturally aspirated and turbocharged four-stroke diesel engines and four-stroke gasoline engines in which the API CK-4 or SN service category and SAE 15W-40 viscosity grade are recommended. It is formulated for engines operating under severe service and a wide range of climatic conditions.

Delo 400 SDE SAE 15W 40 with ISOSYN Advanced Technology is excellent for use in new advanced engines developed to meet the latest emissions and reliability standards and in engines equipped with features like four-valve heads, super-charging, turbo-charging, direct injection, shorter piston crowns, higher power density, intercooling, full electronic management of fuel and emissions systems, exhaust selective catalytic reduction, exhaust gas recirculation, and exhaust particulate filters.

https://www.chevronlubricants.com/en...ae-15w-40.html

[dkoldman]

Originally Posted by NXR

Interesting. Cummins sells OnaMax for far less than others, $6.36 a quart.

https://shopcummins.com/products/cum...31272009826404

With shipping for 6 quarts and tax it came to $9.67 per quart. I didn't feel like driving sixty miles round trip to the nearest Cummins store and that would have cost me $8 in gas anyway. Shipping was $15, or $7 to my way of rationalizing my laziness.

Ray

I guess if you go pick up it will be cheaper? More than a week ago I started with wanting to get the OnaMax. It is at Walmart; but at & $17/quart I think $18/quart on Amazon. I only needed two quarts. I had no intentions of paying ANYWHERE near that much for oil. Thus the Rotella and this thread. Rotella does not carry any API specification for gasoline engines; so I returned it. I bought the the Chevron Delo 400 as it did. Someone told me the Cummins oil was only $6.53, but when I tried to order directly it was $22 / quart. See picture of invoice. I wasn't looking or thinking to add 5 more quarts to try to leverage the shipping cost

I have spent $13 total and I got 4 quarts of oil, 2 quarts are in my 5500 and working like a charm. I have 2 more quarts of Chevron Delo 400 for next September. In May, I will change it out for a pure 30w oil if I can get proof that the pure 30w can handle ambient temperatures significantly higher than 100F of the 15w -40.

FWIW, I get all my oil at Walmart. If I was going to actually buy the OnaMax ( I am not) it would be $17/quart from Walmart (no shipping involved). I have done similar with Yamaha and their Yamalube, and Harley Davidson's branded oil. The difference between those two Mfgs and Cummins Onan is that Cummins Onan IMO has conflicting documents on oil specifications; which may be to deliberate dumbfuse customers so they buy the OnaMax as the only viable solution.

But for now, I am good to go, new Onan Oil filter and fresh oil, I really needed my oil changed the way it looked

[dkoldman]

I actually called Cummins Onan today. Of course I am constrained to the one person I spoke with; but he seemed very knowledgeable

1. He admitted that the various sources of information from Cummins Onan can make it confusing.
2. He says the Rotella T4 15w -40 oil I had at first would have been just fine
3. He says Diesel oils in and by itself is not an issue for Onan gasoline generators, even without a Gasoline API rating
4. He says as long as you have the right weights 15w -40, 10w -30 or Pure 30 you will be just fine.
5. He says No Synthetics and was emphatic about it. I asked why? He states that the Synthetic blends leaves deposits on the cylinder wall. the cylinder block and can damage the exhaust.
6. When I told him about my choice of Chevron Delo 400 15w -40 for Diesel & Gasoline Engines for $13 / gallon; he made me verify that it was not Synthetic, when confirmed he went on to tell me how I must be the smartest & persistent RV Owner with a Cummins Onan Generator ever !!!!!

But I wasn't through

I told him about my plan to switch to a Pure 30w oil in March due to ambient temperatures going above 100F. He said Noooooo!!! He says the 15w -40 is actually better for higher temperatures than the 30w , he went on about viscosity breakdown being the reason.

So I am 100% done. I can use Chevron Delo 400 15w -40 (Non Synthetic) year around and I am very happy with no worries.

[elgraciano]

which ever oil u use. add Prolong oil additive... it is pretty impressive stuff. I have used it consistently on high mileage diesels and gassers...

[Elkman]

Originally Posted by neub

I used rotella 15-40 in my past onan 5500 and have been using the same in my bmw 1300S motorcycle for 11 years...a lot of bmw motorcycle owners use it. This oil is not to be used with vehicles with catalytic converters which of course the onan doesnt have.

All diesel pickups have catalytic converters and they all use diesel motor oil.

I would not worry about oil formulated for diesel engines going into a gas engine but it costs more and provides no benefits in terms of its additive mix. 25% of a gallon of diesel oil is additives to protect the diesel engine from the fuel.

The Onan only takes a quart of oil so replacing it is of little or no consequence.