I have used my 81 300D like a truck.
Pulling a trailer with a Camaro on it across two states.
Pulling a 82 300SD across town.
Taking stuff to the dump, etc, etc...
And I have put a lot of hard, fast miles on it.
Especially right after I bought it.
I wanted it to blow sooner rather than later when I had a bunch of money in it.
The car actually liked the abuse.
It seems to like a good hard Italian tune up.
Somewhere around 300,000 miles now, and she still sounds great.
Except for that loose A/C belt.
Need to fix that today.
Have Fun
RichC