Is 10W-30 Oil Too Thin For Ram 6.7L Cummins Engines?
A reader asks: I’ve got a 2019 Ram 2500 with the 6.7L Cummins diesel. My manual says to use 10W-30 motor oil meeting the MS-10902 or API CJ-4 specification. I’m used to running a 5W-40 or 15W-40 in my previous trucks. Isn’t 10W-30 a bit thin for this engine? Our answer: We can assure you…



