Originally Posted By: dnewton3
Just for info; the 10w-30 T5 has the same cold crank rating as the T6 5-40. And in OH, the dino 10w-30 will suffice very well; my neighbor has had great success with such in the Rotella line, and roadrunner has great success with the JD 10w-30. One does not "need" a syn for such application.
I agree 100%, for whatever reason(s) the "synthetic oil is NEEDED for a diesel or turbo application" has proliferated itself to the point of unbelievable proportion.
The current offerings of diesel engines in domestic pick-ups have proven through UOA's to do just fine with dino HDEO's, with evidence here in our HDEO UOA section.
I actually had higher wear numbers when I switched to a 5w-40 from a 15w-40 several years ago. I then went to a 10w-30 dino and the wear numbers settled back to where they were with 15w-40 or a little lower.
I have no issue running my 6.0 out to the owners manual recommended 7,500 OCI with 10w-30, with UOA evidence to back me up.