TheOldHokie
Well-known member
Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Or alternatively SAE 20 in my manual, Good luck finding an SAE 20 CK4 heavy duty diesel engine oilI believe it's 10w30 in my manual.
I think we got sidetracked with the conventional vs. synthetic debate when the original concern (at least for me) was really 5W40 vs 15W40. I live right on the Mason Dixon line and we still get single digit temps. An SAE 15W40 is simply not a good choice for all season use here. If you want to run a grade 40 all year round a 5W40 or 10W40 oil is a far better choice. Your choices for a conventional CK4 diesel oil in those grades is going to be limited. to say the least. Possibly in 10W40 but I seriously doubt anyone makes a conventional 5W40,
Dan