ive seen STOCK ctd last as long as 300k in person and have heard about a friend of a friend of a friends 12v hitting 1/2 million miles.

with that being said ive also seen brand new 2009 ctd with only 7k miles on them with a blown motor and stacked chips.

i suggest you look over at the ctd forums on this site and ask a few question over there. cause almost everyone here are v8 MAGNUM MEN with the exception of a v6 here and there! lol

 

my CTD has 310K right now with no signs of stopping. ive started the processes of rebuilding it all and most seem to say it will last 800K before i need to do anything major to the engine. i hope they are right *crosses fingers*