85 SD has the more robust engine but it's obviously a generation older - no airbags, maybe no ABS, needs valve adjustments, feels slower (probably is), big steering wheel (some like it that way), etc. Easier and cheaper to service because of its size and availability of new and used parts. About the only downside is the unique turbo and air cleaner arrangement if it's a California car and the transmission and rear end ratio are a single year application.

300D 3.0 vs 300D 2.5 requires a coin toss. 300SD vs 300D is something you decide in a test drive.

Sixto
93 300SD 3.0 - comatose