Does anyone know what the best-ever diesel engine model was that Mercedes-Benz had sold in the USA and Canada (1968 to 1995)?

Candidates:
1968-1976 (all car models are W115 bodies)
OM615.912 I-4 = 220D(/8) (1968-1973)
OM616.916 I-4 = 240D (1974-1976)
OM617.910 I-5 = 300D (1975-1976)

1977-1985
OM601.921 I-4 = 190D 2.2 (W201) (1984-1985)
OM616.912 I-4 = 240D (W123) (1977-1983)
OM617.912 I-5 = 300D, 300CD and 300TD (W123) (1977-1981)
OM617.950 I-5T = 300SD Turbo (W116) (1978-1980)
OM617.951 I-5T = 300SD Turbo (W126) (1981-1985)
OM617.952 I-5T = 300D, 300CD and 300TD Turbo (W123) (1981-1985)

1986-1995
OM601.921 I-4 = 190D 2.2 (W201) (1986)
OM602.911 I-5 = 190D 2.5 (W201) (1987-1989)
OM602.961 I-5T = 190D 2.5 Turbo (W201) (1987)
OM602.962 I-5T = 300D 2.5 Turbo (W124) (1990-1993)
OM603.960 I-6T = 300D and 300TD Turbo (W124) (1987)
OM603.961 I-6T = 300SDL Turbo (W126) (1986-1987)
OM603.970 I-6T = 350SD and 350SDL Turbo (W126) (1991)
OM603.971 I-6T = 300SD Turbo/S350 (W140) (1992-1994)
OM606.910 I-6T = E300 Diesel (W124) (1994-1995)

In other words, this topic is open to those who know what the best diesel model is in terms of reliability (among other quality issues).

Thank you,



Ben (StrokeEightFan)