Does anyone else notice that when you drive over a manhole cover on the road, the back end of the car shimmies sideways as the back wheels drive over the manhole cover? Kind of annoying.

The overall ride on the 21" tires seems harsh to me too. I lowered the pressure to the minimums (they were really high in all tires) and it helped some but still an issue.

Has anyone swapped out their 21" tires for 20"? I assume its some big bucks to do so.

 

I'm not fond of that shimmy either. But, I'm not going to replace the wheels/tires.

 

No shimmying here that I notice, and I think the ride is almost plush, but that’s with E-ABC. Do you have steel springs?

 

Yeap! My 22s do it and I’ve said it a long time ago. The rear end does seem to bounce around over small bumps if hit just right.

 

I don't know about shimmying, but I wonder if you aren't experiencing Tram-lining. Wider tires are notorious for tramlining, where they follow groves and other road imperfections.
https://www.tirerack.com/tires/tiret....jsp?techid=47

 

Maybe it isn't a shimmy and definitely not tramlining, at least for me. Probably more of too much bouncing I guess. There is a bump across half of a 4 lane divided road, kind of like a speed bump but not as large as the winters aren't nice to asphalt in the Midwest, by my house and the speed limit is 45. Every time I go over it, the back end seems to 'bounce' way more than I think it should. It would have been nice to be able to test airmatic. If I stay with MB after the GLE, I look at getting that on the next one.

 

I do not have the ABC on this one. Not sure if its the wider tires in back or just the small side walls on all four tires. I can live with it, and really about the only thing that bothers me with the GLE 450. A great all around car otherwise. I'm going with the bigger sidewall tires on the next one, even if it doesnt look as cool.

 

I agree.
21" staggered non-ABC and the ride is very plush. I do notice a bit of shimmying but then again, my former W166 with factory 20s did the same.

 

I have gone from factory 20”, then bought the 21” staggered, then swapped back to 20”, and now swapped back again to 21”

Along the way I have gone thru 5 complete sets of new tires in about 2.5 years, ranging from 1xContinentals, 1xPirelli, 3xMichelins. 4/5 were UHP summer tire sets, 1/5 (my current) are All Season touring.

Some observations from my experience, the 21” UHP summer tires do tramline in the rear significantly more than the 20” UHP summers. My current 21” a/s touring does noticeably less tram-lining than the UHP summer 21” tires, but still a little more than the 20” UHP.

As for ride comfort, the comparison between 20” vs 21” UHP summers is pretty obvious, the 21” rode noticeably harder. However comparing the 20” UHP summer to the 21 a/s touring, the 20” are still more comfortable but the difference is alot closer.

 

Yes I’ve noticed the back and gets a little loose every now and then over a bump as well-and I only have 20’s. On my vehicle it’s worse the higher the air pressure there is in the rear tires, and of course I still have the original run flat tires.

Have you tried lowering the air pressure to the min recommended level?

 

One thing I quickly noticed was how easily the rear end would tend to slide out for modestly sharp/fast corners, which seems counterintuitive considering how wide the rear tires are. Some of this, though, has to do with the overall suspension geometry as well. Maybe my one experience was an anomaly on cold tires or a slippery spot (I forget exactly), but it was bit disconcerting.

Of course, driving over very slippery surfaces like manhole covers would probably make it worse, especially considering the overall contact area of the tire.