I have run my '87 300D at 90 for a few minutes at a time with brief excursions to 105 on 2 or 3 occasions. The 603 was made to run easily at these speeds, although I feel the time it takes to gain another 10 or 20 MPH indicates the torque curve is flattening out. The aerodynamics of the W124 are the reason it feels so quiet and effortless at these speeds. No speeding tickets (yet) and someday I am going to buy a Valentine One.

When driving fast I always worry about the people in the slow lane, who knows when someone is going to drift into the fast lane, or like I experienced once doing 85 in my '79 300TD (turbo engine) at dusk, I came up on a paint bucket (fortunately empty) in the middle of the lane and struck it. It stuck in the undercarriage and made a hell of a racket as well as tearing the radiator away from its mount and that precipitated a leak near the top of the tank.

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!