Which oil for 21?

[dward]

Time for an oil change and the manual says 10w30 or 5w40 below -18 Deg
Can’t seem to find Rotella 10w30 but plenty of 15w40.
Is the 15w40 an acceptable oil for the new engine?

 

[bcbender]

No 15w40 on the 19+ CGI engines. I use Rotella T6 5w40 in my 20 as I dont see any benifit going to 10w30 since the other is all temp range, just did the second change at 15k miles.. Walmart had the best price and not much more than the Rotella 15w40 T4 I was using on my old 5.9.

EDIT (reason for oil viscosity change is hydraulic lifters in the new 6.7)

 

[Cummins12V98]

Looked it up on the AMZ/OIL site and the only option listed is the 10-30 at under $10 per quart Dealer pricing.

 

[dward]

Thanks for the info.
I finally found some Rotella T5 10W30.

 

[JLEONARD]

Thanks for the info.
I finally found some Rotella T5 10W30.

Agreed not easy to find in stock but my local Autozone had it.

 

[Killer223]

cal ranch and or tractor supply has the valvoline 10/30 diesel oil. i run it in my tractor.

 

[18RamCTD]

I’m using Chevrons new DELO 600 ADF 10W30. So far so good.

 

[jacknife]

I use Valvoline Blue 5-40 .As mentioned do not use 15-40 . When they redid the engine in 19 the tolerances are tighter and you may not get proper lube to all parts .