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I used to run Chevron Delo CI, but I agree with Doug's concerns about high detergent levels. I have gone back to passenger car oils (currently just Castrol 10w-30) but with a bottle of ZDDPlus.

I think its risky to assume the zinc levels are REALLY in the oil in question. Formulae change--even when the designation (CI/CJ, SL/SM) may not.
However, Amsoil/Redline/BradPenn/Royal Purple are probably excellent,safe, choices because they cater to our niche market, I just prefer to dump the additive in myself.

BTW, I posted two staveley analysis of Chevron Delo 400 LE 15w-40 (thats the CJ-4 formulation) last summer. The Zn numbers were between 1275 and 1300ppm.



Greg,were those samples new our used oil.I have noticed that our used oil (between 18/20k miles) have a higher zinc content than new.I assume some of that zinc is from engine wear.We run the same oil in 50+ Dt466's and a 8 road tractiors with NP400 Cummins.