Gas Generator Oil...Is Synthetic OK to Use?

[Barrett-FL]

I use Mobile 1 synthetic in all my vehicles, including our old Bounder but I was wondering if anyone had any thoughts on using it in a generator?

We have a gas powered Onan Marquis 7000 (presuming it's 1995 as is the coach) with only 350 hours of use and I want to do an oil/filter change and was wanting to use Mobile 1 for added protection.

Any thoughts, recommendations or concerns?

Thank you!

[j.smith]

Been using mobil one 5w30 in the last three coaches, engines and generators.

[xjpr]

Royal purple makes straight 30w syn.

[sbleiweiss]

We use Mobil 1 in engine. My auto mechanic said risky to use it in generator because may leak. I don't understand why, but have been using a synthetic blend instead because of what he said. I use Rotella in the generator.

[Trackrig]

Yes, it's fine. And then you only have to carry one type of extra oil and therefore prevents someone from putting the wrong oil in an engine.

I'm using Rotella synthetic in all of my vehicles from gas to diesel (to include gas and diesel gen sets) because it's the only synthetic that has the required additives for the wet clutch packs on my four wheelers also. Before discovering this I used Mobil 1.

Bill

[pop-sicle]

The temperature your running the gen in is a factor remember the gen is air cooled unless it's high end and is water cooled. But that's why you run multi grade to cover different climate temps.

I think of my gen like I do my air cooled motorcycle and run higher grade 20 -50 synthetic
even Onan recommends 10-40

Some will run straight 30 but could be a little thick in colder temperature.

I run synthetic in everything I own including lawn mower.

[okcnewbie]

Originally Posted by sbleiweiss

We use Mobil 1 in engine. My auto mechanic said risky to use it in generator because may leak. I don't understand why......

He doesn't either. ..... no problem using full synthetic in generator or anything else.

[okcnewbie]

Originally Posted by Barrett-FL

We have a gas powered Onan Marquis 7000 (presuming it's 1995 as is the coach) with only 350 hours of use and I want to do an oil/filter change and was wanting to use Mobile 1 for added protection.

Any thoughts, recommendations or concerns?

Thank you!

After reading past 5 in this thread I switched to 15w50 M1 synthetic in both my kawasaki and generator

http://www.airforums.com/forums/f448...gen-71813.html

[okcnewbie]

I meant post 5 in the above. ...

[marjoa]

Originally Posted by xjpr

Royal purple makes straight 30w syn.

This is what I use.

[George Schweikle]

I remember back when Mobil 1 was introduced. It was said to leak past engine seals (or piston rings) in high mileage engines that had used regular oil. Urban legend or not, back then a co-worked claimed this occurred on his car and the oil consumption was severe. I use Mobil 1 in our gas motorhome and two Alfa Romeo Spiders.

Originally Posted by sbleiweiss

We use Mobil 1 in engine. My auto mechanic said risky to use it in generator because may leak. I don't understand why, but have been using a synthetic blend instead because of what he said. I use Rotella in the generator.

[OldDoggy]

I use a straight 30w synthetic from Family and Farm, Mega brand I think it's called.

[astrnmrtom]

Uh ohhhh. . . beware the dreaded oil thread!

Yep, synthetic is fine and can handle higher operating temperatures in an air cooled engine. The stories of synthetic causing leaks is an old one, and most are from long ago when synthetics became more common starting in the 70s. Synthetic oils have better cleaning properties and the leaks were caused on older engines because the synthetics cleaned the gunk build up inside the engine left behind by older conventional oil, which revealed existing leaks plugged by the gunk build up.

My generator is due for an oil change and I'm going to put synthetic in it.

[RM travelers]

My gas Onan 5500 gen calls for 15w-40 with CF-4 rating. & says not to use synthetic during warranty period. Only 15w-40 with CF-4 is diesel engine oil. But I still use 15w-40 full synthetic Amsoil, changed oil & filter twice now. We’ll see how long gen will last.