After months of deliberation, I recently purchased a set of 20” custom wheels. I spent a great deal of time making this decision because I knew that going from 19” to 20” wheels and tires would alter the ride quality - one of the main reasons I drive an S-Class.

My last 19” tire was the Michelin Pilot Sport All Season 4, which was fantastic. Comfortable ride, no noise, low degradation, and responsive during spirited driving. With all that in mind, I chose to purchase the 20” variant when I stepped up to 20” wheels.

However, after having the 20” wheels and all season tires installed, I immediately noticed a drastic change in the ride quality. Even in Comfort mode, the ride was excessively harsh and I felt every imperfection in the road. Moreover, the serene quiet of my cabin was invaded by road noise and tire drone over most surfaces. The car looked better with the 20” wheels, but the drawbacks suddenly had me very concerned.

I drove it like that for a while, thinking maybe I would grow to accept it. I didn’t. In fact, I became embarrassed to have passengers in the car. The tires and wheels were within factory specs, so I was confused as to what was happening. There was no way that Mercedes would approve of this size and tire combination if it led to such an awful ride. Eventually I checked the owner’s manual and discovered that Mercedes does not recommend all season tires if the car is paired with 20” wheels.

With this new knowledge in hand, I did some research on Tire Rack’s website and selected the Continental Extreme Contact Sport 2. Next, I returned to my local Discount Tire to work out an exchange where the store manager was awesome and setup a fair deal.

With summer tires as opposed to all season tires mated to the 20” wheels, the car returned to its proper behavior: silent interior with a gentle ride, yet capable performance on demand when desired.

I just wanted to share my experience for those who may be considering a similar change from 19-inch to 20-inch wheels and tires.

 

That’s very interesting to know. Thanks for sharing this. I have factory 20’s and have thought of going down to a 19” set. I think I’ll keep my current setup.

 

Good info. I have 20s on mine. Wish I had 19s but do not drive enough to justify a change.

 

So - appearance vs performance...

To each his own.

 

OP, what were the 20" All Season tires you originally bought? I'm sure you already know to only put a high end tire on this car, the mid and lower tier tires don't provide the quietness we expect. I'd love to see the specs on that tire because you might have also exceeded it's load rating.

When I had my 2001 S600 20 years ago, I tried mid priced tires and had terrible results. I didn't understand how load ratings affected the ride quality back then. I remember the first time I had to replace tires I wound up going through 4 sets to get to a tire that was right, each time spending more money.

Post some pics of the ride with your new setup. Curious to see what wheels you chose. Hopefully you chose forged or flow formed.

 

The Michelin Pilot Sport All Season 4. As described in the narrative, I chose that tire when I had 19" wheels and loved it; however I quickly learned that I would have to use a summer tire instead. The previous Michelins and new Continentals are of course extra load and the wheels are forged.

 

Interesting, I have the Pilot Sport AS4's on my car and they are wuper quiet. I just bought them in December of last year and had intended to remove them for the summer, but thye ride as smooth and quietly as the PS4 summer set I took off in December. Sorry yours didn't work out.

The primary reason I didn't change back is because I couldn't decide on a set of Summer wheels. Please post some pics of your new wheels, if you haven't already. I'd love to see what they look like and how they hold up over time. I was goinf back and forth about forged or rotary forged, mainly becaus of price. Hard to justify the expense a set that will only be used 4 months of the year. Great job choosing a forged set!!

 

Yeah I love and highly recommend the Pilot Sport All Season 4 to anyone looking for an ultra high performance all season. In my case, I had to go through the time and expense of realizing I could no longer use all seasons on 20" wheels, but it's still a great tire. I chose Continental summer tires because of the ratings on Tire Rack, but I'm still a huge fan of Michelin.

As requested, here's a pic from today:

 

Beautiful car...wow, your paint looks like liquid metal!! Nice

 

I’m curious, where in the manual did you find it saying no All Season tires in 20 inch wheels?

I thought about going to 20 inches, but the summer tire only may deter me..

 

There is a section in the owners manual called "wheel and tire combinations". In my 2015 S550 manual only summer tires are listed for the 20" wheels. Manual indicates all-weather and winter tires can be fitted on 19 and 18" wheels.

 

Car looks great - all you need now is the Benz Ninja reprogram to return it to Euro ride height. That 1" drop really helps the look when the car is just sitting imho.

I am taking notes on your tire choice. I have the "silent" Bridgestone 20"s on my S63 now and while they are very quiet and grippy, compliant and soft-riding they are not. Will look into Conti's next time. Had them on my 740iL back in the day and they really did ride nice.

 

Looks like the car is in the "raised" height mode. My S550 rode lower than that for sure in normal mode. H emust have raised it so we'd get a better look at the tire/wheel package.

 

Thank you! I truly appreciate that! I do my best to try and keep it well maintained.

 

Yep! That's exactly where I located this information in the 2016 manual.

 

Actually, it was in Comfort mode. I started it, let it run for a few seconds, and then backed out of the garage. When it's in Sport mode, it sits lower for sure, but for Comfort, that's it's normal ride height.

 

Interesting...maybe it's just the lighting, for some reason it looks like there's a larger than expected gap between the tires and wheel arches. Again, hard to see it well with the lighting. No doubt you know about changing the ride height with the button on the center console. I always thought the car didn't lower in Sport mode while sitting still, and lowered automatically when reaching a pre-determined speed. My 2017 didn't change ride height while sitting still when changing driving modes, at least I don't remember it behaving like that. Regardless, that's a beautiful car!!

 

Let's back up for a minute. The S65 uses 20" non-run flat tires. These tires are available in Michelin PS All Season 4 for the S65. also as Alpins if a dedicated winter tire is needed. The owners manual for my car shows 20" all season and dedicated winter tire fitments, the only restriction is tire chains cannot be used with the 20" tires.
I suspect the issue was not looking for the correct tire size. With 20" wheels and non run flat tires, it is necessary to use the AMG sizes of 255/40F and 285/35R to get the desired tire types since only AMG's used non run flat factory tires. The car will ride better on the wider tires as well.

 

You're right about the AMG variants. My S63 uses 255/40F & 285/35R RF's, but a W222 S550 uses 245/40F & 275/35R, run flat or non run flat. What difference would that make for the OP??

 

First difference is they cost more. Second difference is the car will look better with the wider tires. Third difference is the car should ride a little better with the wider tires and rear traction will be slightly better. I know of no other downsides. I have done this substitution on my 2006 S65, it made a major improvement in, handling, ride and rear traction.

 

Thanks for sharing your experience . From my experience : Thicker sidewall doesn't constitute itself a better ride quality at all . My daily W212 has 18" wheels and rides better than 17" wheels even with the same Michelin Pilot Sport Series tires . However, W222s with 20" tires have better ride quality than my car . I can also concur that wider tires deliver better ride quality and traction .

 

Actually, the 18-19" wheels, with maximum performance tires perform better than larger wheels.
where better means:
a) more traction,
b) more grip.

The only reason to put a wheel larger than 19" on a car is to fit bigger brakes.
Yet 99% of people who fit excessively large tires on their cars leave the puny brakes with it.

AND I disagree that bigger wheels "look" better !!