best oil to use for generator and chev engine

[Golf_Guy]

I will be spending all my time in the SW and want to know what the best oil is to use in Onan 7000 and a Chevy 8.1 gas engine. Any thoughts ? synthetic or regular?

[free_radical]

I always use what the vehicle manual recommends
That said
Castrol oil comes highly recommended by the mechanics I know,,so as long as is proper viscosity I use that.
Synthetic is not worth it's extra cost imo unless you have a turbo or run the engine extra hard in extreme temperatures..

[hondapro]

Chevron Dello 5-40 synthetic

[Monaco_Montclai]

My engine book says on the 6.8, 5/20for the 6.8. Been good for 23k, so far. Now it's all happy-camping

[chiefneon]

Howdy!

X2 on thw Shell Rorella Synthetic T6 4W40. I use it in everything I own truck, car, generator, ATV, lawnmower etc...

"Happy Trails"
Chiefneon

[tpi]

Golf Guy wrote:
I will be spending all my time in the SW and want to know what the best oil is to use in Onan 7000 and a Chevy 8.1 gas engine. Any thoughts ? synthetic or regular?

I don't think you could go wrong with 5W40 synthetic in both of them. Such as Shell Rotella Synthetic T6 5W40.

[wilber1]

Whatever you use, be sure it meets or exceeds the manufactures spec for the engine. They have good reasons for specifying what they do and they aren't always obvious.

[K3WE]

DownTheAvenue wrote:

Golf Guy wrote:
I will be spending all my time in the SW and want to know what the best oil is to use in Onan 7000 and a Chevy 8.1 gas engine. Any thoughts ? synthetic or regular?

The best oil is what the manufacturer recommends! Read your owner's manuals.

Oh come on...God forbid anyone think...No, we must be mindless drones and follow instructions blindly.

The OP is wondering if the same oil might be used in both- and he's not a nut job.

There's a halfway good chance the genny and motor might allow the same viscosity ratings.

There's also a chance that the viscosity is the same, but that "quality grade" might differ. That being said, if you could put the higher quality oil in the "lower quality engine" with minimal risk.

There's another chance that the vehicle might have a short list of oils and the genny a long list of oils that will give him an overlap.

And (prepare for flame war) he might even want to say to hell with it and put the vehicle oil in the generator even though it's wrong. Pretty good odds the generator 1) Will not explode into a ball of flame and 2) Will purr along and outlive the rest of the RV with the high-quality, very slippery, albeit wrong motor oil. (His choice, not ours).

[colliehauler]

I run the same oil Rotella T-6 synthetic 5w-40 in both.

[DownTheAvenue]

Golf Guy wrote:
I will be spending all my time in the SW and want to know what the best oil is to use in Onan 7000 and a Chevy 8.1 gas engine. Any thoughts ? synthetic or regular?

The best oil is what the manufacturer recommends! Read your owner's manuals.

[xaugievike]

My two cents is that filter and oil change intervals are more important than the oil type.

That said, I run full synthetic on everything (Mobil 1 on gas engines).

[1492]

Moved from Forum Technical Support

[n7bsn]

RTFM
See the manuals and follow their directions. The manufacturers know the engines better then anyone else and their directions would be better then some "expert" on the inter-webs.

[Grandpere]

I use Castrol 20-50 high mileage oil in both my generator and the 454 engine. Better viscosity and the generator doesn't use anymore oil than when I used a straight 30 weight oil, which I am having a hard time finding anymore, hence the change to the 20-50 oil. I also add SFR100, and additive that boosts the viscosity of the oil in both engines.

[2oldman]

Synthetic oil 2014

20 demerits for posting in FTS.