10-4 and thanks for the explanation.
AH64ID wrote:
Per Cummins OEM fill is Valvoline Premium Blue Extreme 5w-40, as they don't know what climate or season it will be sold in.
:S LOL, but I don't know if info is accurate, or I'm getting a favorite oil survey.
Lets see. One service manager tells me Rotella 15W/40 (where I bought the truck). Another says Rotella 5W/40. Then there was the odd one who said Valvoline Premium Blue but in 15W/40 weight.
Good grief! You know, one could not even add a quart(if needed), with any degree of confidence that you were adding the correct oil to the motor.
Anyway, glad I changed mine at 3200 miles. At least I do know what is in there now.