Amsoil small engine 10w40 or Shell Rotella T6 or whatever else you recommend. It sounds like some guys use diesel oil. I think it takes a quart or less so price is not an issue.
Factory rec is 15w-40 diesel oil, but Amsoil small engine would be phenomenal for that engine due to its super low noack and it just being a great oil in the first place.
Originally Posted By: FermeLaPorte
Chevron DELO would be a better fit since diesel oil is HDEO, AMsoil is boutique meaning just for show
Why do you think this?
Let's get a fix on exactly what this engine is, and I can recommend an Amsoil oil that is very stout and more suited to the exact generator application than a generic HDEO.
Originally Posted By: pkunk
Originally Posted By: UncleDave
I ran M1 0w40 in my onan 4K "microquiet" as its pretty cheap and I always have a lot on hand.
Rotella will be fine if not great
No filter on that genset - splash only lubrication.
It does have a nice altitude adjustment on the carb.
It drinks like a sailor consuming about 1/3 GPH at a constant 3600 RPM even idling.
UD
Mine is the 5500, has a filter and runs at 1800 rpm. Much more effecient and quieter
You sure about that?
The 5500's Ive run are 2400 RPM units.
Quieter nicer and a big step up from that 4K for sure, but I didn't think it had an 1800 RPM head ??
Any 15w-40, sae30 or 20w-50 will serve you well. It is all I use in onans.
I do not own your model, but I do one two.
The one is a 4.5kw the other a 5.5kw. both have quite a few thousand hot hard florida hours on them.
I only used sae40, 15w-40, or 20w-50. Ran "3600" filters and did 150hr drains.
I've always used 15W-40 in the Onan generator in the 3 motorhomes I've owned. I use Shell Rotella 15W-40 which is easily obtainable at any auto parts store or Walmart. With my first motorhome I called the local Cummins Onan service center and asked specifically about the Shell Rotella oil since it's diesel motor oil. They said it's a good oil to use in diesel, gas or propane generators.
However, I would like just go with what the owners manual says.