Hi, I've got a 2011 E550 Cabriolet with 18" wheels, 235R45 tires on front, 255R55 on the rear. I've tired of the harsh ride, and am looking for advice.

It appears suspension parts are the same for the E550 and E350 Cab, which leads me to conclude switching to 17" wheels with higher profile tires may make a significant enough difference.

I'd greatly appreciate any advice offered regarding the idea, suggestions for wheel widths and sources, and tire sizes.

TIA.

I don't have too many suggestions but I can tell you this the more rubber you put between you and the road the softer the ride 👍

On my ‘11 E550 coupe I run Michelin Pilot Sport 4S that are a size bigger than stock - 245/265. Ride is great as is the grip. They also fill out the wheel wells better.

Thanks for the reply...I suspect that your solution would go the wrong way for my desire, which is for a more "luxury" ride rather than "sport". My goal is less for the sports car ride I drove for decades and more for softer.

Yeap - it’s all relative. My E550 is “luxury” compared to my ‘04 GT3 which my wife refers to as “the Flintstones Car”.

I have a 2013 E350 4matic Coupe that originally came with 18" staggered wheel/tire (8.0 x 18 (45mm), 8.5 x 18 (49mm)) set-up. The OEM tires were MB-specific, Michelin MXM4 Primacy M&S (235/40 R18 91, 235/40 R18 91). The prior owner had recently replaced the front tires but the rear tires were original with approximately 46,000 miles.

I decided that I wanted a non-staggered wheel/tire setup to allow for wheel/tire rotation. I also wanted a smoother ride. I considered going from 18' wheels to 17" wheels but I decided to stay with 18" wheels.

After a great deal of research, I selected Vredestein's Grand Touring All-Season tire, the Quatrac 5, The Tire Rack reviews for this tire were very impressive, including a numbers of reviews from Mercedes 4matic owners. For my setup, I purchased tires in the 235/40 R18 size which was the size of the front tires.

After 4500 miles, I am extremely pleased with these tires the overall smooth ride of these tires, I live in the Northeast US (Connecticut) and these tires work for all seasons.

I used the Tire Rack local installer program and this worked smoothly.

When I replaced the tires and wheels, I also replaced the TPMS sending units. I purchased these genuine MB-logo TPMS units on ebay. They have worked perfectly.

I hope this information helps you with your tire decision.



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Thanks for the detailed info, SMG CT. I'll look into the Vredsteins. I hadn't thought of switching from offset wheels; I imagine going to 17" would be an even bigger change towards what I'm after...although I'm still not certain the 350 and 550 suspensions are identical.

Mark,

What you might have missed here in this suggestion was that when he went up from 235 to 245 in front, and from 255 to 265 in the rear, he kept the aspect ratio the same, which means the sidewall heights of the larger tires are also taller, so the result is that he now has a softer ride due to the increased tire diameter/sidewall height to act as a shock absorber for bumps in the road. This would help some, but stepping down to some 17" wheels from an E350 would probably provide you with the biggest ride quality increase, mainly because of the additional sidewall height of the 17's. I hope this helps!

Thanks, vrmmm, yes, I didn't notice, and didn't realize the sidewall was taller...thanks for pointing it out. I felt that, as you note, that an even taller sidewall with 17" wheels would get me closer to the soft ride I want.

Cheers.

First up, what tyre pressure are you running. The OEM level are on the high side and will make for a firmer ride, so just dropping a couple of PSI may may all the difference for you.

You aren't going to get a huge difference even with smaller wheels with a bigger profile unless you also swap to the SE model springs and shocks. But you may get enough for your needs.

Thanks for the reply, 400ixl, I've run various pressures with not much noticeable difference. Right now it's factory recommendation. Switching out spring is probably a great idea, but doubt it's cost effective. Maybe it's time to either continue to live with it, or find a new ride.... I do remember driving a couple E350 cabs, and thinking they were more compliant...which goes back to the question whether the suspension bits are the same on the two models.

On the 350 you will have had the AMG Sport models which have a firmer suspension and 18" wheels like the 550 or the SE model which have softer suspension and 17" wheels.

That settles it, then, without the softer springs there's not going to be the difference I'm looking for.

Thanks to all for the suggestions and advice. I'll have to think this over.

Hey Mark-
Any progress to report? I have a 2014 E350 Convertible with the factory Sport Package and the Michelin Pilot Sport A/S 3+ tires. Rides waaayyyy too firm. Would love to soften things up a bit. Would consider suspension change or drop to 17" wheels/tires, just not sure where to start.
MM

I just put Michelin Pilot Sport 4 AS on my 2012 E 350 with the sport package and it is a night and day difference! The tires I had were 225/40-18 in the front and 235/40-18 in the rear which the first tire dealer insisted was correct. It wasn’t. When I looked at the sticker in the door jamb it listed the required sizes as 245/40-18 in the front and 265/35-18. I went with the larger sizes and it was a huge difference! The tires are quieter, smoother and don’t break my
teeth when I hit a bump. I originally wanted Michelin Primacy tires but they don’t make them in the right sizes for my car but I’m extremely happy with the Pilot Sports!

BTW the other tires weren’t worn out I just hated them and wanted them off of my
car!

Very good info and timely for me. I've got (and will keep) the 18" rims on my Sport. I've bought Continentals for several vehicles and have been satisfied - except for the set of ControlContacts on the car now. About 25k miles in them, still have tread, very even wear, etc.but they are NOISY. To the point where all wheel bearings have been checked. I know noise will increase after time, wear, rubber degradation, etc but this is excessive to me. I've even got additional sound dampening in the trunk and rear seat area. I'm not expecting tomb-like quiet but the sound is ridiculous. Discount Tire will pro-rate them to my next choice and I've been looking at the oem Conti's as I've had better past experience with them. But for sure I'll look into the Quatracs, to be honest I've not heard of them.