Gathering info on mb diesel generations
 

If you were to start from the early 70s until current diesel motors of todays Mercedes how would they rate against each other under the following Catogories.#1 Long life, #2 Servicability DIY, #3 MPG, #4 POWER.

1) descending
2) descending steep
3) ascending
4) ascending

Time will tell for #1
But the other categories I think most would agree.

Long Life
Equal= 617, 606, 648, and slightly lower because of the head 603
All will get you to 250 easily, and plenty of 400,000 mile examples to be found

Serviceability
617, 603, 648, 606

Mileage
648, 606, 603, 617

Power
648, 606 if turbo, 603, 617

each includes variants of the same family, IE: 616/617, 603/602 etc