Forum Discussion

camp104's avatar
camp104
Explorer
Mar 19, 2018

Onan 5500 generator

I I am going to do an oil change on my Onan generator I would like to put synthetic oil in it. Does anybody out there use synthetic oil in their generator and what weight do you use. I have a 2005 Bounder 35 e
  • fourmat wrote:
    I have an Onan 5500 and Onan told me absolutely not to use multi vis synthetic unless it was to be operated in very cold temps and then 10/40

    WHAT?
  • fourmat wrote:
    I have an Onan 5500 and Onan told me absolutely not to use multi vis synthetic unless it was to be operated in very cold temps and then 10/40


    That's odd. I and several other people called them two or three years ago and we were all told it was fine to use synthetic oil. There were a bunch of posts about back it then.
  • I have an Onan 5500 and Onan told me absolutely not to use multi vis synthetic unless it was to be operated in very cold temps and then 10/40
  • camp104 wrote:
    Thank you I also use Mobil 1 synthetic in the RV now I will put it in the generator I also use 10 W 30 thanks for the reply


    The same stuff you use in the RV will be fine.
    In my case, I put Rotella T6 in both. 15W40 I think.

    Edit: it's actually 5W40
  • Thank you I also use Mobil 1 synthetic in the RV now I will put it in the generator I also use 10 W 30 thanks for the reply
  • Onan said synthetic oil was okay to use. Based on the temp range in which I used my generator I used 30 weight dino oil. When I switched to Mobil One synthetic oil in my motor home I used 10 W 30 weight - the same weight dino oil I used in it - that is also what I used in the generator. Only had to carry one weight of oil that way.