Summary: Good news: Two ZEREX products meet all four specs for Detroit Diesel: These are ZEREX (618-1) Extended life and ZEREX Precharged (Fully-forumlated) See the Tech bulletin websites described below for info on Cat,Mack, and Cummins. I submitted the following to Valvoline (ZEREX) via e-mail: I would appreciate your advising me which of your antifreeze meets DD specs. DD specs include DD 1925M, 1899M, TMC RP 329 and bulletin 7SE298. I am specifically seeking formulations which include nitrite to avoid cylinder liner cavitation pitting. I received the following reply: Thank you for your question! Zerex recommends that you use one of the following three coolants, Zerex G-05, Zerex Extended Life, or Zerex Pre-Charged. Whitney Harrison Technical Specialist The Valvoline Company 800 354 9061 ext. 7838 >From the Valvoline website: ZEREZ G-05 (part # ZXG051 and ready to use ZXG05RU1) gallons A HOAT (meets three of four specs: RP 329 not stated) Life of antifreeze not stated Phosphate free, fully formulated (contains nitrite) (I previously incorrectly posted that it did not contain nitrite.) Whiteny is checking with a Valvoline chemist to further assess why G-05 does not state RP 329 is met.) ZEREX 618-1 Extended Life Six year life, 14,000 hours meets all 4 specs Requires ZEREX extended life extender.;;.incredibly their website says nothing about how to test nor when to test nor when to use the extender....Whitney says says add extender at three years... ZEREX Pre charged ("precharged (partZXPC1) and precharged ready to use (part ZXPRU1) ) gallons meets all four specs life: 1 year, 150,000 miles guarantee fully formulated (this should mean it contains nitrite) low silicate Further descriptions of the above products may be found at http://www.valvoline.com/pages/products/category.asp?cid=2&print=1 Tech bulletins are at: https://www.valvoline-technology.com/data/VALV/ValvExtSecurity.nsf/f sZerex?OpenFrameSet Cheers, Rob Brueckner 1972 Hatteras Yachtfish