Been running T6 in my â€˜16 Cummins Ram for 90k miles...seems to work just fine. Ready for another change and WM was out of t6, so picked up 3 jugs of TDT At $2 more per jug (24 vs 22) What are thoughts on 5w40 TDT these days? I recall it was highly regarded once, but haven't heard much about it since. Versus rotella...better, worse, or the same? TDT has two ingredients listed: severely hydrocracked something (grp3?) and zddp. Nothing else.