Newer oils have LESS ZDDP (ZINC) 850ppm or less for CJ-4 and SM oils.

For your diesel you want CI-4, CI-4 Plus and CJ-4

For a ideal of the Mobil Delvac oil with the CI-4 Plus rating is 1700ppm zinc very high

Here's some for Mobile one which list there API and zinc contents.

Mobil 1 Turbo Diesel Truck 5W-40 zinc 1200ppm
Advanced full synthetic formula
CJ-4, CI-4,
CI-4 Plus, SM,
SL



Mobil delvac MX 15w40 (Now that's some good oil) zinc content is over 1000ppm

API CI-4, CH-4, CF, SL, SJ