Community Forums

bmurph44 · 04-11-2015, 08:45 AM

I'm trying to decide what oil to put in my 2012 year Onan/Cummins gas generator. The manual says to use the 15/40 or 30 weight for the temp range in my area but never mentions using synthetic. I have Rotella 15/40 in my garage but didn't think a diesel oil would be good for a gas engine, I couldn't find straight 30 weight in synthetic so I bought regular 30 weight. So it's either regular 30 weight, Rotella 15/40 or synthetic 10/30. My gut feeling is go with the 10/30 synthetic and call it good. Looking for suggestions experiences etc....

mel s · 04-11-2015, 08:53 AM

Quote:

Originally Posted by bmurph44

I'm trying to decide what oil to put in my 2012 year Onan/Cummins gas generator. The manual says to use the 15/40 or 30 weight for the temp range in my area but never mentions using synthetic. I have Rotella 15/40 in my garage but didn't think a diesel oil would be good for a gas engine, I couldn't find straight 30 weight in synthetic so I bought regular 30 weight. So it's either regular 30 weight, Rotella 15/40 or synthetic 10/30. My gut feeling is go with the 10/30 synthetic and call it good. Looking for suggestions experiences etc....

bmurph44

Why would you even think about using 10/30 if your "manual says to use the 15/40 or 30 weight"?
Mel
'96 Safari

mccrob · 04-11-2015, 08:55 AM

Air cooled engines want a 15/40 heavy duty oil. Rotella fits the bill for everything from your generator to your Harley

bmurph44 · 04-11-2015, 09:04 AM

Quote:

Originally Posted by mel s

bmurph44

Why would you even think about using 10/30 if your "manual says to use the 15/40 or 30 weight"?
Mel
'96 Safari

Because the manual says I can use that weight it just covers a broader range of outside temps plus I can then go to a synthetic oil.

bmurph44 · 04-11-2015, 09:05 AM

Quote:

Originally Posted by mccrob

Air cooled engines want a 15/40 heavy duty oil. Rotella fits the bill for everything from your generator to your Harley

Thank you, I think this is what I'm gonna use.

AFChap · 04-11-2015, 09:19 AM

Rotella would not hurt a gasoline engine ...might have a bit more detergents than a gas engine oil. Diesel oils are not as different from gasoline oils as they used to be. I don't waste money on synthetic oils (if I did, I would use a slightly higher viscosity). Good quality Dino oils changed annually (I have not yet exceeded the mileage or gen hours change interval in 12 months) will keep my rv engine and generator running well for longer than I will need it.

bmurph44 · 04-11-2015, 09:29 AM

Quote:

Originally Posted by AFChap

Rotella would not hurt a gasoline engine ...might have a bit more detergents than a gas engine oil. Diesel oils are not as different from gasoline oils as they used to be. I don't waste money on synthetic oils (if I did, I would use a slightly higher viscosity). Good quality Dino oils changed annually (I have not yet exceeded the mileage or gen hours change interval in 12 months) will keep my rv engine and generator running well for longer than I will need it.

And this is also what I was thinking.

dennis45 · 04-11-2015, 10:26 AM

Quote:

Originally Posted by AFChap

Rotella would not hurt a gasoline engine ...might have a bit more detergents than a gas engine oil. Diesel oils are not as different from gasoline oils as they used to be. I don't waste money on synthetic oils (if I did, I would use a slightly higher viscosity). Good quality Dino oils changed annually (I have not yet exceeded the mileage or gen hours change interval in 12 months) will keep my rv engine and generator running well for longer than I will need it.

Good advice. One oil (Rotella) for the engine and generator. Keep it simple. Unless you are operating in some severe environment, such as -40, synthetic oil is a waste of money. IMHO

bmurph44 · 04-11-2015, 02:05 PM

All done, used the Rotella 15/40, that was the closest to all the recommendations in the owners manual.

becks · 04-11-2015, 07:32 PM

Like those above, I too have used Rotella 15/40 in both engine and genny on all three MH's we have owned.

Tha_Rooster · 04-12-2015, 05:34 AM

I just changed engine and genny yesterday I put rotella 15-40 in both and always have.

bmurph44 · 04-12-2015, 05:58 AM

Quote:

Originally Posted by becks

Like those above, I too have used Rotella 15/40 in both engine and genny on all three MH's we have owned.

I have the Ford V10 in my coach so I will continue to use the Motorcraft 5/20 synthetic blend oil as the manual says, it's a good oil that is priced reasonably and is what I have always used in my Ford F150 pickup, it even uses the same oil filter as my pickup.

Tha_Rooster · 04-12-2015, 11:48 AM

Quote:

Originally Posted by bmurph44

I have the Ford V10 in my coach so I will continue to use the Motorcraft 5/20 synthetic blend oil as the manual says, it's a good oil that is priced reasonably and is what I have always used in my Ford F150 pickup, it even uses the same oil filter as my pickup.

Good choice, 15/40 is for DP'S.