I had a 1980 300D non-turbo and it was very slow with the automatic trans. I test drove a, admittedly piece of junk, 1982 240D with manual trans recently and it seemed pretty peppy, for a non-turbo diesel. I was quite surprised. About 200k miles on it, rear bumper fell off, rusty front end, good interior though.

I guess my point is try both cars and see which one you like. I kinda like the manual trans, and the speed was reasonable (non-life threatening I thought) so I'd probably go for it. If you like auto trans, then get a turbo 300D, forget the non-turbo. That auto trans might shift for good fuel economy but you're always flooring it for speed.

Also, if you want options and buttons (power windows and locks, for example) you may have to go with the 300D.

Miles, whoa, 300,000-500,000 average with regular maintainence. Might need an auto trans in that period. Be sure to review the previous owner(s) service records. If there are no service records, it's harder to determine how long the car will run.

Again, try both. For me, it comes down to if you want a manual trans or auto. 240D for the manual, 300D turbo for the auto.

Good luck!

-m

__________________
Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC