After few phones calls and lost of post of several forums, I just learned that Onan now recommends 10W30 for gas generators
https://www.cummins.com/generators/m...-rv/onamax-oil
As OP, I find this excellent!!! Make you wonder if the phone calls to Onan Support a while back had any impact?
This opens the doors to common sense and afford us many more legit & safe options.
Because of the avantage to support lower temperatures over 15-40, I will likely switch from my Chevron Delo 400 to a regular 10w - 30 oil as I use for my autos, portable generator, lawn mowers and even the RV itself. Now, (in future) I can carry 1 quart of 10w 30 on RV that can be used to top off engine or genset if needed.
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