Valvoline Premium B is not only endorsed by Cummins, it's formulated in accordance with what Cummins wants in an oil. It could just as easily be a Cummins branded oil endorsed by valvoline.

At the Tech center we have massive tanks of PB-- the 55 gallon drums are too small to use effectively.

 

I started out useing chevron delo 400 15W-40 at 30,000 miles I switched to schaffers full syn. supreme 9000 5W-40.I can buy the schaffers for $16.53 gal.

 

Touchy subject. Everyone has thier opionon. Just use delo, amsoil, schaffers, mobile, volvoline, etc... I personally use Royal Purple. I have tried them all. The one that I liked most was royal purple, so I stuck with it. They are all good. If your worried about money, then buy the cheapest of the above brands.

 

I run Caterpillar DEO in mine.