Forum Discussion

rbrand's avatar
rbrand
Explorer
Oct 17, 2017

Onan fuel consuption

I have a Onan 4000 generator.
would anyone have an idea of it's fuel consumption. Hours/ Gal?
  • The range between a light load, say 750 watts and a heavy load, perhaps 3,200 watts is considerable.

    Cut and paste - this is listed on Google


    rv2go

    Fulltime 14 yrs (Knoxville, TN).or someplace else

    Senior Member

    Joined: 12/26/2000

    View Profile




    Posted: 08/28/11 11:18am Link | Print | Notify Moderator
    From Onan:
    4,000 watts
    33.3 amps
    LP vapor generator is 3,600 watts with 30.0 amps
    Gas generator consumes an average of .5 gallons of fuel per hour at half load.
    LP vapor generator consumes an average of .6 gallons of fuel per hour at half load
    3,600 RPM
  • Thank you Mexicowanderer. That was quick. Right now it is parked in my backyard masquerading as an earthquake emergency kit. I wanted some idea of how many hours of power I could get with a full tank of gas. Now I know.

    Thank you
  • dont forget when you calculate run time, that gen will stop pulling fuel on gasoline models, somewhere around 1/4 tank on most rv's
  • charging batteries watching TV
    fridge, WH etc om LP
    approx 1/4 gal per hr

    running the A/C approx 1/2 gal per hr

    running the fridge and wh on electric using the genny is a big waste of gasoline fuel, especially in emg situation when you might need to stretch that fuel
    set fridge and wh, LP only use the LP heater if needed
    A/C well if needed that has to be the genny
  • When we go to the races, the generator usually runs 12-16 hours a day, for the 2 days we're there, it usually consumes 11-12 gallons of gas.
  • Onans are very fuel efficient whether gas or diesel. I had an Allegro with a 4KW onan gas genny and now have an Onan 7,500KW diesel and they both oue less than a gallon an hour at full load.Kasr winter I ran the Onan diesel for 14 hours at half load and it took 10.5 gallons.
  • See page 20 for fuel consumption specs.

    http://www.joshwakefield.com/xplorer/onan-microquiet-4000.pdf

    Oh what the heck, why not just read the entire manual while you're there!

    Chum lee

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,188 PostsLatest Activity: Jan 17, 2025