JUst to weigh in with anecdotal evidence: my father ran a 74 240D for 24 yrs ----- when the fuel formula changed (mid 80's?) he was 500 miles away from home visiting my sister. On the way home, the car stopped several times, always restarting when cooled. He finally finished the trip on a flatbed (I'd have loved to see him & my mother crammed into the cab of a tow truck for a couple of hours). His mechanic told him to use 5 0z of ATF per 10 gal of fuel to supply the lubrication that had been taken out of the fuel -- to lube the IP. He also told my father about the chance of being cited by the feds, so my father chose to use Lubro Moly diesel hi-test most of the time instead. With extra lube added to the fuel, the IP never stopped again, & there were no repairs done (that my father can remember). With that as a guide, I ran an 86 Jetta diesel bought very used for 5 yrs, at least 100K (no odometer the whole time), using ATF most of the time, and Lucas injector cleaner & additive -- avail at truck stops in gals or in many auto parts stores in smaller bottles -- diesel rated -- whenever the engine started more slowly. Fast starting was always restored with one treatment. That engine still ran well when I sold it, no repairs or IP troubles. I am doing the same regimen with my 84 240D, 12K so far with no troubles except glow plug replacement.