300SD 5cyl i am running moibe1 20w50 for diesel but i feel it way to thick the speed doe stop at 189,000 when i bought it so miles on engine are ???? but who ever own it before my kept up on it it looks like it was a sales mens car all highway miles it came with all the records in the owners manual it show to use regulor motor oil but i work on heavy Equ we used high detergent diesel oil 20 w 40