Ours are small pull start 2000w generators. This winter I may try some 0w30 and see what happens. I have started it on gas to warm it up. Then I just turn off the gas and switch over to LPG.
I don’t have to use the generator much anymore. When I first moved off grid last year I was waiting on solar panels and had to charge my batteries every few days. I converted to propane because it was about $2 a gallon cheaper at the time and I could let it run for 20 hours at a time Without fueling. I hate the smell of gas on my hands and gloves.