Forum Discussion

bsheet2's avatar
bsheet2
Explorer
Aug 04, 2019

Generator Oil Change Frequency

The gen set in my Thor Challenger is an Onan QG 5500 Gas. The RV manual says change the oil every 150 hours. That seems pretty frequent. If boon docking when it is hot we could do that many hours in a couple of weeks.

Any idea if this is correct?? Every 150 hours of run time??
  • bounder39zman's avatar
    bounder39zman
    Explorer II
    Aug 05, 2019
    Onan dealer/cert. tech here 30 + yrs. As OP's have said, oil is cheap.
    150 hours on your genny is equivalent of 6000 miles on your vehicle.
    And remember, this is basically a lawn mower engine. So yes, Onan says 150 hr,or annually, but personally, I do 100 hrs or less on gasoline;
    150 hrs on diesels. In my part of country (Southeast), 15W-40 works great year round for both air cooled gasoline units and diesels.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,189 PostsLatest Activity: Jan 19, 2025