The best true generator I ever had was a Powertech generator made in Leesburg, Florida.At the time, they were being used by Prevost.It was a 7,500 watt generator head powered by a Kubota D-905E 3 cylinder diesel engine.It ran smooth, and quiet.It was in a 24x24x36 aluminum box, and it was the quietest I have ever heard.At the time, it was 5 grand, but you also had to put a rooftop a/c unit on the roof, and an espar for heat.It was the best of all worlds.Nearly trouble free.
Later on, on a different truck, I used a cheap Power pro gas generator, 3,200 watt, from Pep Boys, and with alot of oil changes, using Delvac and lucas, it lasted 14,000 hours.Not bad for a $300.00 generator.I had a 10 gallon fuel cell for the gas mounted under the cargo box next to the generator box.Never had an issue with it from the dot, etc.Just drove up to a gas pump, and gassed it up, which lasted around 3 days.The truck was 13'6 high, also.
Now, I have a Cummins/Onan P3200ie portable gas genarator that is super quiet, on a basket mounted to a hitch on the front of the van.I hate the setup, having it there, but there is no other place to put it.It runs a 15,000 btu Hengs Industries rooftop a/c, who makes the units for Dometic, and it will freeze me out of the 12'cargo box/sleeper at all times. The a/c unit weighs 80 pounds on the roof.A Honda 3000 is comparable to this generator, which I will be getting next, since finding out that Cummins only made this generator for 2 years.So far, this setup is trouble free, for the most part.It has a 3 gal gas tank, that runs for 20 hours without the a/c on, and 8 hours with it on.Kinda a pain in the butt, gassing it up every 16 hours,(Have a 3 gal gas can also)but, so is going to a repair shop also.
Sometimes simple is the best route to take, and makes better financial sense.Just sayin.