I use 15W40 Delo in my dino engines, still has the zinc additive.
ALL of the diesel rated oils, including DELO 400 have reduced the zinc and phosphorus additive by about 25%. Anything with a CK-4 rating will have reduced ZDDP. I have used DELO 400 in my diesel for years and the attached oil analyses shows when they reduced the additive package. If you can find CJ-4 rated oil (good luck), that has the higher ZDDP additive. Seems like all diesel rated oils have been scarce lately, no matter what the rating.
But using a diesel rated oil in a gas engine is still a good thing, as the additive package is higher than a straight gas rated oil.
