5W40 or 15W40 in 6.7 CTD?
So the owner's manual in my 2015 Ram says to use 15W40 oil in the 6.7 Cummins diesel, unless the temp is going to routinely be below 0*, in which case you should use 5W40. Here on Long Island, the ...
Forum Discussion
blofgren wrote:
It would probably make no difference as long as you aren't exceeding the mileage specifications. I'm not the least bit worried about the 1 year OCI that I have been using for several years now.
You are correct. The time frame of 6 months doesn't matter as long as it is changed with a certain mileage or engine hours. As I stated earlier, no oil analysis would be able to tell the difference between 15k mile oil at 6 months or 15k mile oil at 12 months. The 15k interval with the Cummins is even with non-synthetic 15w40.
