Gone are the days you could find diesel oil at any shop and didn't have to be a chemist to understand if it was safe for your engine. I'm not convinced CK-4/SN oils are reliable for our diesel engines, I see CK-4 formulations of the same oil (ie Rotella) with less of all additive levels and now no Moly. There's a few oils I see that are safe now: Motocraft diesel oils I think are safe, Ford seems to agree with my assumptions, even with them carrying CK-4 Ford is adamant about 1000ppm phos. Shaeffer 9000 5W-40 is still CJ4 (last I checked) Harvest King, still CJ4? (made by Warren oil?) Lucas Magnum CJ4 (and CI4) Delvac MX (but this is Ci4... may have to look closer into this one, this oil isn't on many shelves though) Any others out there that could be suggested?