Synthetic Oil In An Onan Generator

[Hooligan2]

The small Onan generator oil is changed often and may not benefit from using a synthetic. Your choice. I use Rotella T4 15w40. A quality dino oil.

Oil has come a long way from the bulk oil drum and non specific jars of oil that I remember.

[lwmcguire]

Originally Posted by Hooligan2

The small Onan generator oil is changed often and may not benefit from using a synthetic. Your choice. I use Rotella T4 15w40. A quality dino oil.

Oil has come a long way from the bulk oil drum and non specific jars of oil that I remember.

As a kid I worked in a station in the evenings and weekends. Your choice was weight and detergent or non and we had the quart bottles just like your picture

[mountainsam]

Yes that bottle brings back memories of Hudson Oil Co. my first job in 1961. Recycled oil, 10 cents a quart.

[lwmcguire]

Originally Posted by Hooligan2

The small Onan generator oil is changed often and may not benefit from using a synthetic. Your choice. I use Rotella T4 15w40. A quality dino oil.



Oil has come a long way from the bulk oil drum and non specific jars of oil that I remember.

I fully agree with the value if you stay with the 200 hours

Using premium filters and synthetic I extend the change interval 100 hours

Our newer JD equipment was 500 hours

Every one has to go with what they feel is right for them

[XJPR]

Royal purple has 30w synthetic, you usually have to order it,i get it from Murrys

[Glensouth]

I have used Amsoil full synthetic in my generators for the last 18 years with no problems. Makes it run cooler and the engine has less ware. Good luck.

[wingnut60]

Gritz Carlton--

"The oil lines are smaller to generate higher flow rates and quicker cooling." Would you expand on how to get higher flow rate with a smaller line? Did you mean to say "generate higher PRESSURES "?

[lwmcguire]

Very true, velocity will increase but not gpm

[10scDust]

Originally Posted by wingnut60

Gritz Carlton--

"The oil lines are smaller to generate higher flow rates and quicker cooling." Would you expand on how to get higher flow rate with a smaller line? Did you mean to say "generate higher PRESSURES "?

Agree here too!
They taught me, resistance to flow equals pressure!

I have been asked if having 50+ oil pressure is good on their motorcycle.
My question, in mind, is what is it not doing (flow) to create such pressure?

[ArmstrongRV]

Originally Posted by ddlonewolf50

Good question , I would call Onan and find out what they recommend.

I called Onan and they said SAE 30 or 10W30 only.

[jabrabu]

I use the oil that is specifically made for Cummins gas generators, and for my specific climate range -- Onamax 15W-40.


I did the first oil change at 50 hours, and then every 100 hours after that.



https://www.amazon.com/Cummins-32653...5505c9d1e&th=1

[Mulerider]

I've been using synghetic Amsoil in all my engines since the 70's. I use 10-40 small engine by Amsoil in my 5500 generator.

[Metalman]

I use diesel type oil, 15w-40 in the Onan generator and have for several years. However, when I lived in NH and attempted to start the generator on a very cold winter day, it was sluggish and didn't start. So I went to 10w-40 or 10w-30 (can't remember which) and the problem was solved. I don't think it matters whether dino or synthetic oil is used, but since I change oil based on time (every year) rather than hours, I use dino oil. The generator has a lot less than 100 hours when I change the oil.

[v_chat]

Don't have an Onan diesel in our MH, but our food truck has an Onan QD 12K (upgraded recently from a 10K). We use Shell Rotella T5 10-30w. With it running a lot (sometimes 10-12 hour shifts), the oil is changed every 500 hours, along with a fuel filter change. Also use a K&N air filter.

One thing to be careful about that we learned from our previous 10K when it was rebuilt, was to turn off the generator when operating in a sandy/rocky area, at least when driving in those conditions. The sand and rock particles can damage the generating rotor components. Cummins/Onan techs told us this handy tip!

[happy]

Great tip. I would not have thought about shutting down the gen while on gravel and dirt roads. That fine dust has to be damaging to some extent.

[Metalman]

Originally Posted by v_chat

...turn off the generator when operating in a sandy/rocky area, at least when driving in those conditions. The sand and rock particles can damage the generating rotor components. Cummins/Onan techs told us this handy tip!

Thanks for the info. I will try to remember that when driving in sandy locations.

[apr67]

Originally Posted by 10scDust

The little I remember being taught about oils, in a multi-grade, it is man made polymers mixed into the oil (being straight weight to begin with), that makes it thicken its viscosity as its temperature rises, (the polymers binding together to force the oil to thicken).

Not exactly. Multiweight oils are rated on viscosity at two different temperatures. The first number is its rating at -22F. The second rating is at 212F.

The oil doesn't thicken, it just doesn't 'thin' as much because of the viscosity improvers.

https://www.belray.com/what-exactly-...gnations-mean/

[Bob Denman]

Originally Posted by Hooligan2

The small Onan generator oil is changed often and may not benefit from using a synthetic. Your choice. I use Rotella T4 15w40. A quality dino oil.

Oil has come a long way from the bulk oil drum and non specific jars of oil that I remember.

I agree... Sure you can use it: but why?

[Metalman]

Back in the old days we had to use thinner (lower viscosity) oil in the winter and thicker (higher viscosity) oil in the summer. Then came mulit viscosity oil that was often referred to as constant viscosity oil. A 15W-40 oil has the characteristics of SAE 15 oil at low temperatures and the characteristics of SAE 40 oil at high temperatures.