Onan 5000 Gold to Synthetic

[Low_Bridge]

I have a Onan 5000 Gold with about 750 hours


it's in my 2001 Aventurer.


Opinions on changing oil to synthetic?


Thanks!

[armullis59]

I have only used synthetic oil in my cars and trucks. Not sure about a generator! You might want to talk to a Cummins dealer about it and certainly look at the owners manual.

[Old Crows]

If you have 750 hrs ..... use what you have been using, it appears to work well.



I'd check the ONAN manual or search on line, to see what is recommended by Sir Onan.

Probably more important is the 'grade' of oil to use. On our Onan 3600 LP, I use 15W40 year round because that gives the broadest coverage for temperature extremes. Good to about 5F (-15C) to over 100F. Good enough.



FWIW.... a Crow's Opine.... no charge....



There is little difference between a 'synthetic' and 'dinosaur' oil today. If you look at the back of the bottles or visit the websites, you will find that either one meets the same API/SAE/ACEA specifications. In fact, non-synthetics have to use 'synthetic' additives to meet the tougher standards today.



What do I use in the genny? 15W40 Onamax. Sort of 'old school' meeting SAE SL requirements last I looked. Why? because it is air cooled and that's what's in the manual. I don't know if ONAN has a special blend or not. But gas/lp air cooled engines have different requirements than diesels.

[lotsoftoys]

Cummins is fine with using synthetic oil on gasoline and LP generators after the initial break-in. They just want you to maintain the same service intervals.

[jerichorick]

Originally Posted by Low_Bridge

I have a Onan 5000 Gold with about 750 hours


it's in my 2001 Aventurer.


Opinions on changing oil to synthetic?


Thanks!

Check your manual and see what the lightest weight oil you can use for the temperatures you will be in. The lighter the grade the quicker the pump can get it to the critical spots when starting. I have used Royal Purple for years in all of my engines: car, coach and generator. 10W30 is recommended in the manual. 15W40 for high temp running. But, my coach is all diesel.

[Dennis L]

If you check on the internet, you'll find that the only truly synthetic oil is Amsoil and Mobile 1. The rest are highly refined dino oil.
When Castrol came out their "Synthetic oil, Mobile 1 sued them and lost.

[carlwatson]

Originally Posted by armullis59

I have only used synthetic oil in my cars and trucks. Not sure about a generator! You might want to talk to a Cummins dealer about it and certainly look at the owners manual.

hello from auburndale Florida I swapped over to the synthetic oil for both my main engine the V10 Ford and my Onan generator it has worked out excellent it does extend your time between oil changes on vehicles and I sometimes we'll go half again on hours between oil changes on the generator. Now have over 2,000 hours on that generator and it runs like brand new also remember to use a gas conditioner if you're using 87 ethanol fuel your generator will love you for it

[SnKPerk]

Any suggestions on oil for a diesel generator ?

[Old Crows]

Originally Posted by SnKPerk

Any suggestions on oil for a diesel generator ?

It would be helpful to have the make/model of your generator.......