Before, I have been using Shell Rotella 15W40 Diesel oil because of its high zinc content. I was reading on another thread, that now even this oil has lower zinc phosphate content. The one I was getting before had the CI-4 rating, the ones in the store now have the CJ-4 rating.
I found some other diesel oil, 15W40 with CH-4 and CI-4 ratings. I don't know who makes them, as they are packaged under the stores own brand.
Anyone know if all CH-4 or CI-4 rated diesel oils would have a higher zinc phosphate content?