Onan 5500 Gas Generator - suggested oil?

[ependydad]

I know the weight of oil I will ise (15W-40), but any suggestions on specific brands or types?

(Yes, I know this can get controversial.)

[dinkhauler]

I'm planning to use royal purple full synthetic in mine. Pennzoil platinum and Mobil 1 are also great.

[2Evil4U]

If it's natural gas it will run very clean. If you're going to have less than 150 hours per year, and you intend to follow the change frequency, I'd go with an inexpensive non-synthetic. I'm an amsoil dealer but I don't waste money on synthetic unless I'm running extended drain intervals.

[ependydad]

Thanks guys. I hope to buy 100% gas as much as possible, but I don't often come across the stations that have it, so I get by with whatever I have to.

I have no idea how many hours per year we'll run it, but I do think it's safe to assume it'll be less than 150. We put maybe 30 on in a few days of boondocking and periodic exercising of the generator.

[lcv800]

I use Onan. I know it's pricier but if I ever have an issue? Besides for two quarts once a year compared to what I drop on everything else, it's a drop in the ocean.
Rusty

[CHICKDOE]

i also use onan. 2 qts a year. i cannot verify this but somebody i respect told me that the onan oil is made by valvoline.

[ependydad]

I didn’t realize there was an Onan oil.

[TTED]

This is a couple days late but for the difference in price I would ALWAYS run a synthetic oil. It doesn't break down as easily.

I've been an auto technician for 43 years.

Happy trails, Ed

[mecapeman]

Cummins Onan Generator
Model: 5.5 HGJAB-1119J
S/N: J150886578
Oil information:
15W40 Non Synthetic Valvoline Premium Blue
API Rating, SJ, SJ/CH4, SH or SG
Cummins part # 326-5336

Cummins cross referenced their part number with a NAPA part #.

The NAPA part # is 75122

Also the Cummins cust svc person said if the oil has an API rating of CH4 that will work.

[ProfChuck]

After the break in period, try adding Motor Kote additive to whatever oil (I don't use synthetic any more, except in my snow thrower and generator) at 1 oz. per quart of oil used. This stuff really works well and I don't burn oil in anything I have put it in. Available at many stores.

[2Evil4U]

Originally Posted by ependydad

Thanks guys. I hope to buy 100% gas as much as possible, but I don't often come across the stations that have it, so I get by with whatever I have to.

I have no idea how many hours per year we'll run it, but I do think it's safe to assume it'll be less than 150. We put maybe 30 on in a few days of boondocking and periodic exercising of the generator.

I misunderstood. That is a gasoline powered unit? Interesting. I'd always figured fiver generators would run off the propane tanks. Still doesn't change my recommendation.

[ependydad]

Originally Posted by 2Evil4U

I misunderstood. That is a gasoline powered unit? Interesting. I'd always figured fiver generators would run off the propane tanks. Still doesn't change my recommendation.

It's a toy hauler, so I have 2 x 30 gallon gas tanks on it. One for the generator + one with a fuel pump.

[ependydad]

Originally Posted by mecapeman

Cummins Onan Generator
Model: 5.5 HGJAB-1119J
S/N: J150886578
Oil information:
15W40 Non Synthetic Valvoline Premium Blue
API Rating, SJ, SJ/CH4, SH or SG
Cummins part # 326-5336

Cummins cross referenced their part number with a NAPA part #.

The NAPA part # is 75122

Also the Cummins cust svc person said if the oil has an API rating of CH4 that will work.

I looked up the 15W40 Non Synthetic Valvoline Premium Blue oil and got concerned when it said "premium diesel engine" oil so I called Onan. The woman who answered confirmed that's the oil that I should use.

Local AutoZone has it and I'll pick it up tomorrow for a Saturday oil change.

[trdutch]

Originally Posted by lcv800

I use Onan. I know it's pricier but if I ever have an issue? Besides for two quarts once a year compared to what I drop on everything else, it's a drop in the ocean.
Rusty

I agree ☝️

[ependydad]

Originally Posted by lcv800

I use Onan. I know it's pricier but if I ever have an issue? Besides for two quarts once a year compared to what I drop on everything else, it's a drop in the ocean.
Rusty

I agree and normally I would. But, I need to get the oil changed this weekend and can't find the Onan stuff near me. Fortunately, calling Onan, they recommended the Valvoline.