Diesel Onan Generator

[jeepsrule]

My Onan has run for 66 hours this last year, mostly on the road running A/C. I'm getting ready to do maintenance on it and I'm considering switching the Onan to synthetic oil and running it for two years on an oil change. Does anyone have experience with this or comments??

I've had extremely good experience with synthetic oil in gas autos now for two decades.

[OneRVer]

This will be my third year on Amsoil. However I do change the filter, Donaldson, each year. I did an oil analysis last fall and past with flying colors. I will be changing the oil and filter this fall. I do the same in my CAT 3126.

[jeepsrule]

So you don't change your Cat engine oil every year? I love the synthetic oils but I've read many posts that had seeping from the seals when they changed to synthetic in a used engine. My Cummins has 35,000 miles on it.

[OneRVer]

That is an old myth. I have used Amsoil for over 20 years in old or new engines and transmissions. Never had seepage. I bought a 97 Buick with 67,000 miles on it. Started using Amsoil on my first oil change. Sold the car with 219,000 miles. No oil leaks. Used this oil in the engine and transmission.

Same with my RV. All bearing's are greased with synthetic, rear end is synthetic as well as the engine and transmission.

No, I am not an Amsoil Dealer. However I am a Preferred Customer.

[ga traveler]

I have been using moble 1 for three years now, with no leakage. It works great.

[Buford B]

It's only 3 quarts of oil. Change it often. Use the same oil as in MH KISS.

[jeepsrule]

All for Keeping it Simple

[spike45]

Quote:

Originally Posted by OneRVer That is an old myth. I have used Amsoil for over 20 years in old or new engines and transmissions. Never had seepage. I bought a 97 Buick with 67,000 miles on it. Started using Amsoil on my first oil change. Sold the car with 219,000 miles. No oil leaks. Used this oil in the engine and transmission. Same with my RV. All bearing's are greased with synthetic, rear end is synthetic as well as the engine and transmission. No, I am not an Amsoil Dealer. However I am a Preferred Customer.

That is NOT an old myth. It is true that some seals can experience compression set in the elastomer compound meaning the seal material hardens. Changing from standard mineral base oils to PAO synthetic oils (poly alpha olefin) does affect the sealing ability just like the change from higher sulfur fuel to ULSD did the same for old fuel pump seals. Replacing seals and running from new with the new base oil will work fine unless you switch back to mineral base oil or could get high sulfur fuel again.

Based on a lawsuit brought by some oil companies engine oils that have been hydro treated or hydrocracked can now be called synthetic. True synthetic oils are formulated from PAO. If you can determine the type of base oil used, you should see that a true synthetic is Group IV while hydro cracked mineral oils are Group III. There is a difference in performance. That is why you may not experience leakage when you switched to a "synthetic" oil.

Why do you need a synthetic for such low hours operation and likely not at much real engine load?

[Dirtbuster]

Quote:

Originally Posted by spike45 That is NOT an old myth. It is true that some seals can experience compression set in the elastomer compound meaning the seal material hardens. Changing from standard mineral base oils to PAO synthetic oils (poly alpha olefin) does affect the sealing ability just like the change from higher sulfur fuel to ULSD did the same for old fuel pump seals. Replacing seals and running from new with the new base oil will work fine unless you switch back to mineral base oil or could get high sulfur fuel again. Based on a lawsuit brought by some oil companies engine oils that have been hydro treated or hydrocracked can now be called synthetic. True synthetic oils are formulated from PAO. If you can determine the type of base oil used, you should see that a true synthetic is Group IV while hydro cracked mineral oils are Group III. There is a difference in performance. That is why you may not experience leakage when you switched to a "synthetic" oil. Why do you need a synthetic for such low hours operation and likely not at much real engine load?

I see that someone knows what hyrdocracking is! One example is Motor Craft oil, made for Ford!

Well stated!

[spike45]

In 20 years working with Caterpillar, I never learned quite as much as the last 21 years at Fleetguard (Cummins Filtration). I have gotten a choice education and have relished it. Wide range of topics have been studied in pursuit of supporting customer's inquiries.

Thanks