The Mercedes dealer told me my '91 300SE wanders and is subject to cross-winds because:

I replaced the 205/65/15 (ET= 21.5) with
225/55/16 (ET = 23) from the TireRack.

I put these on several years ago, and was as happy as a clam.
But at some point I noticed the car was susceptible to a wander
on the hiway.


I tried all the usual stuff over the course of several years:
Steering box, all the suspension parts, bushings, subframe bushings, etc.
everything you guys here suggested. Car is as tight and solid as when new,
But just moves around on the highway, especially if there is any wind.

So, the dealer got the nod.
They couldn't find anything to suspect - every component was great, alignment was good.
So, he blaimed the wider, bigger wheels.
'Hey Bud, you put on bigger, wider wheels and tires, of course it will affect the high-speed stability".

Is this possible?
Everybody changes wheels, even Mercedes went from 14" to 15" during
this model's life. And the offset ET is correct per TireRack.
Ever heard of 16" wheels causing a really nice car to wander around?
It's been doing it for 6 years, so it's not a bad tire or component I don't think.

Tks,
DG