Hi,
I have a 2007 RAM 3500 w/ the AAM 11.5 and a cummins engine.
I just installed a EATON Truetrac in the rear and I don't know if I should get:
1) DELO ESI 80w90 (non-synthetic)
or
2) DELO ESI 85w140 (non-synthetic)
I tow a 8k every two months or so, and drive in SoCal most of the time. Never...