A guy came today to do some core drilling for me on a couple of walls, he had the quietest generator I have ever heard a 12.5 MQ was made by Denyo of Japan had a Isuzu diesel engine but was assembled in the USA fine piece o equipment
He told me he paid less than 7,000 for it in the quite box said it would run 2 days under load on 5 gals of fuel that one I question lol might be something for you to check out it made for use not like the rv stuff
Here's some data I've found --
Denyo -- DCA-10-SPX Cummins Onan HDKCA - 10
10 kW 10kW
61 dBA (23 feet full load) 69 dBA (10 ft.1/2 load)
3 cyl/ 24.5 HP Engine -- 1800 Rpm 3 cyl/ 27 HP
Fuel cons. 1/2 load - .58 GPH 1/2 load - .43 GPH
1142 Lb. 765 Lb.
So, it looks like the Denyo is almost 400 pounds (~45%) heavier, *way* bigger at 30 Cu/Ft versus 15.7 Cu/Ft (won't fit in my bus), similar size and HP engine, and 61 dBA full load/23 feet versus 69 dBA 1.2 load at 10 feet. Dunno how in the h*ll you'd compare those sound level numbers.
@ 1/2 load, the Denyo would burn about 28.8 gallons in 2 days; about 25% more than the Cummins.
Is the Denyo a better generator? I dunno, but it won't fit in my bus. FWIW, HTH, BH NC USA