I've been through all kinds and sizes of tires on 123 cars. What I want is well balanced, round, long lasting tires because I drive 50k ot 60k miles per year 95% or more at highway speeds.
I prefer Michelin 195/75 14 regular passenger car tires, I have gotten as many as 85k miles out of them. The 75 series tires are cheaper, and harder compound for longer wear.
Regardless of the brand or size, the most important thing on these cars is to ENSURE that the #@%$&#! people at the tire store set up their machine for and put weights on the inside AND the outside of the wheel. I have to watch them like a hawk. I don't know how many times I've made a big deal about this and they still put weights only on the inside of the wheel. Their reason is that "most people don't want weights on the outside because they look bad". If you don't have them balanced this way on one of the computer balancers, or the person doesn't recheck the balance after installing the weights, you will have minor nagging problems and decreased tire life.
The front end on these cars are sensitive to this. If the tire is not balanced radially AND axially it will never feel right.
If you put on a good set of Michelins regardless of size and have them balanced properly, these cars will run at 100MPH (unless it's a 240D, then we'll say 90) as smooth as silk.
Absolutely insist on weights inside and outsided of the wheels.
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in