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
otrfun wrote:
Sounds like a perfectly legtimate explanation to me. If this is the case, gotta wonder what specific issue in that 6 mo. to 12 mo. MTBF/OCI data pushed their warranty costs high enough to warrant a 6 mo. OCI? Hhhmmm . . .
I don't think it is a specific issue per say, but rather a way to get out of paying if they the owner is stupid enough to tell them. That would be the only way they would find out since they would never know with a UOA. I can see why the old 2007.5-2012 Ram Cummins engines with out DEF would need a 6 month interval due to contamination from how often the EGR is being utilized, but not the 2013+.
Here is another ISB/B-series maintenance guide realized by Cummins for motorhomes that was updated in Dec-2018 for the new engines as well. While the "new" engines did not show up in Ram's until 2018, they were already in other applications since 2017.
Motorhome Maintenance and Operation
B6.7TM, ISB6.7, ISB5.9, B5.9 Engines (200-360 hp)
