I was recently re-amazed at what a difference quality tires can make on our heavy benzes. I'd been going with Dunlops on our 300TE, and even with plenty of tread left it was getting scary to drive - very squishy and non-confidence inspiring. With 13 years and 182,xxx miles, I know some suspension components may be at the limit which possibly exacerbates the issue - but -
ditched the trashy Dunlops and went with Michelin Pilot XGT's. Night and day - much crisper handling, especially turn-in and lane changes.
89 MB 300TE
84 BMW 733i
01 VW EV GLS