what weight MOTOR oil do you use in your GAS motor home and GENERATOR

[Gary RV_Wizard]

The original onan manual calls for SG, SH, or SJ spec. Those all appear to be out of date. What API specs do I use for a guide?

API specs in the same series are downward compatible. That means that SL, SM, SN etc all exceed the SJ spec and can be used in place of it. However, the SJ spec is still "current" and you can likely find SJ spec oil on the shelf in farm supply or marine stores.

 

[decaturbob]

I use whatever the specs call out and use the synthetic version