I have a 2013 SL on order. Build date in early December. Question regarding the run flat tires.

Years ago I had a car with run-flat tires and the ride was harsher than with regular tires. My current car is a 2011 SL. The ride quality is excellent and I am concerned that with the 2013 I will be losing some ride quality.

Does anyone have any feedback or comments on how the run-flats affect the ride quality or handling?

Thanks,
Mark

 

I can only compare the ride against my old 2005 SL.

The 2005 did ride better but I can't say I am disappointed with the ride of my 2013. The handeling is superior and performance puts my 2005 to shame. So, I guess, in the end, when you add up all the plusses and minuses... the run flats are a non issue for me...

 

I have a 2013 w/ the 19" AMG sport package. I was also concerned about a harsher ride w/ that combo. I always enjoyed the ride on my previous SL equipped w/ 18" AMG wheels and standard tires. I have driven the 2013 SL in Europe and here finding the ride just as enjoyable as my previous 2003 SL. I find no noticeable difference between the 18" standard and the 19" run flats. I believe suspension upgrades have made this a none issue.

 

I too have noticed the harsh ride in some cars with run-flat tires. I even switched to non run-flat Nitto Invos on my 2008 Z06

Mercedes must have done some of their magic with the suspension. I don't notice any harshness in my SL550.

 

I have the 19's also and agree, no harshness to the ride and no road noise compared to other run flats I've had.

 

Interesting situation. I hope that all of you are smarter than I am. I drove my new SL550 for weeks and felt every bump in the road. Then I noticed the sport/comfort button on the center console. I was driving in Sport mode, when I switched it to comfort it immediately became as smooth and comfortable as my wife's new E550 sedan!!! Perhaps you are in the wrong driving mode.

 

I finally picked up my new SL yesterday. Love the car.

But I can definitely tell that it is a harsher ride than the 2011 SL that I just turned in. Even in the normal suspension setting.

Not sure if it is the run flats intrinsically. Or maybe that the runflats have to be inflated to 35 psi instead 30 or 32 psi on the tires on the 2011 model. I might try deflating the runflats down to 30 just to see if I can notice a difference. (Won't leave them at 30; only for the experiment)

Note that I am saying that is is a slightly harsher ride, not an unacceptable ride. I love the car so far!

 

I run mine at 32/32 psi unless I'm on a trip. Then I pump them up to 36/42 or a bit less. (just in case the urge overwhelms me. I'm usually heavy on trips too)

I believe I can feel the difference in ride. Let us know what you find.

 

I traded a 2007 SL550 for the 2013 SL with run flats. I agree with the post that indicated a rougher ride on the RFT's. I have tried various pressure levels but returned to factory requirements. I'm now getting used to the ride and other advanced features of the car. I do have loss of pressure in these tires which I think is abnormal,the dealer says it's the weather.Really?

 

The Continentals on the 19" are better than the Bridgestone RF's I had on my BMW 335i, but they are not as smooth as the Hankook V12's that I used to replace the Bridgestone tires on the BMW.

On the BMW I kept an inflation kit with the car and never had a problem, but I always worried a little on a long trip without the RFT's. I am sure replacing one of the 19's in rural Texas would be a challenge so I am willing to put up with the ride on the RFT's.

 

I also can feel little harshness on my SL (19 AMG wheel, no ABC). However,

my previous car was 335i vert with RF and it was the painful ride ever. Even

worse than my C63 AMG...

 

I have the 19's also with no ABC and yes on certain roads with certain types of imperfections the ride is harsh on comfort. On other roads it takes the bumps very well.

I am plying with the tire air pressure to see if it makes a difference. Going too low at a certain point actually seems to make the ride harsher rather than more compliant.

 

I have had a couple R230's with ABC and two 2013 SL550's; one with springs and one with ABC. Both have the 19" sport wheel package on it. I have also replaced the run flats with the 19"/20" forged AMG rims with the excellent Michelin Pilot Super Sports.

In short, springs are harsher than ABC independent of tires. So coming from an R230 to the R231 will experience a stiffer, less adjustable ride (albeit a very nice one).
MB's Run flats are much better than the Goodyear Rft's on our BMW, which are horrible, but still inferior to non runflats.
Mercedes has done a great job calibrating the suspension to deal with the stiffer sidewalls.

 

My 6 month old 550 has (had) the OEM Bridgestone Potenza run flats. I was at the Sears Point Raceway, attending a high performance driving school when, at the apex of the slalom course, my left rear "found" the only piece of debris on the paddock. It was a small bolt, like what holds fenders and so forth to motorcycles. About 3MM in diameter, and maybe 14MM in length.

It completely penetrated the tread, dead center in the tire. I was "flat" within 50 feet. I will say that my tire pressure sensor system immediately informed me that I had zero air pressure in the LR tire. Of course I knew that already.

I limped around the course to a tire service center that's located on the raceway grounds. Of course the tire could not be repaired. Secondly, even in the San Francisco area, 19" tires are scarce. Very, very scarce.

The tire shop manager spent 30 minutes calling every tire store within 30 miles, for a solution for me. He finally found a tire shop that was 17 miles away in San Rafael, that had two used Pirelli's in the correct size. This was after more than 23 phone calls.

I started out for San Rafael at a moderate speed. I had to proceed on Hwy 34 for the first 9 miles since there isn't any other way to get there from where I was. I'd recently read the manual regarding the run flat's characteristics, so I knew that speed was not my friend. But at the same time, I didn't want to be hit by an idiot motorist. So I drove the first 9 miles at 45 MPH.

As soon as I could, I got off the highway, and drove the remaining 8 miles at 20MPH, or less. I mean I crept thru the back roads of San Rafael, as slow as I could go. I also stopped every 10 minutes or so, to let the tire cool down. I did this when I realized that the funny hot rubber smell was coming from me.... and it was NOT a good smell.

Eventually I arrived at the tire shop in one piece. As I got out of the car, and stepped around it to enter the office, I heard (and saw) the sidewalls of my LR tire collapse. Just folded in like wet cardboard....

An hour later I was back on the road with my two used Pirelli P-Zero's... and never happier! As soon as I returned home (about 90 miles away) I ordered a set of Michelin Pilot Sport AWS tires, and had them installed as soon as they arrived from the Tire Rack.

I've driven the Pilot Sports for about a thousand miles now, and they are far superior in both ride comfort, and in handling when compared to the OEM Bridgestone Potenza's. No comparison in fact. I've driven the same roads that I did with the Bridgestones, and it's an amazing difference.

I will say that the difference isn't as noticeable on a good surface freeway, but when I'm traveling a windy "slalom" turn mountain highway, the handling is markedly improved. Plus on rough roads the ride is also much improved... even in the "Sport" suspension setting.

And that's my story....

Chris

PS: I now have two "Slime" tire inflation kits in my trunk... along with my AAA towing card... If the Slime doesn't work, then it's AAA.

 

Wow, Chris, that is some adventure story. It may keep me up at night!

While I do not think it was the smartest purchase, I let my dealer talk me into spending $1,899. for a 5-year "Tire & Wheel Protection" Insurance Contract -- when I found out that my 2013 SL550 did not have a spare tire. This policy covers 3 nights in a hotel, $100 in towing, 3-day car rental, etc., for both tire and wheel damage/replacement. I sure hope I never need it. But I may get my money back damaging a rim or two on one on New Jersey's many monster sized potholes.

While it is an old comparison, my Lexus SC430 hardtop convertible came with run flats that were hard as a rock. After 5k miles, I could not take it any longer and replaced them with Michelin Pilots. What a BEAUTIFUL difference in every way. It was like driving a totally different car.

My Original 18" OEM SL run flats are significantly better than the old Lexus RF's. However, I am still tempted to replace them with non-run flats, probably Michelin Pilots. But I will not do this until after my original SL RF tires wear out. They look half-done at 5k miles.

 

I think I agree with you on your evaluation of the $1900 you spent. I've got AAA with their 100 mile flatbed "tow" service ($100 annual membership), the road hazard warranty on my new Michelin Pilot Sports for $24 a tire. Between my auto insurance, and AAA, I'm covered for a rental car for as long as it's needed.

On the wheel repair (and your Jersey potholes), I've found that KwicksilverUSA does excellent wheel repair work. I had my RF wheel repaired by them for a total of $225, which covered the "curb rash" refinishing, and the straightening of the wheel's "out of round" condition. They did an excellent job, and now my RF wheel looks better than the rest.

The thing about "run flats" is that the sidewalls are what allows the tire to run without air pressure. So they've got to be "stiff"... unfortunately, as far as I'm concerned, the run flat capability is what makes them a poor choice for a good road tire.

The other alternative to run flats (besides a real spare tire), is a tire inflation kit, or in MB speak "TireFit Kit". These sell for about $75 or so, or you can get a non-MB tire inflation kit from Slime, for about $35 each. Since I don't have the run flats on my 550, I got two of the Slime inflation kits, and they're in the bottom of the trunk. Where I hope they eventually decay over the next 10 years of non-use.

I just did a 2300 mile road trip from Sacramento to Seattle, and return. The new tires made a huge difference in both comfort, and in handling. I'll never ever use "run flats" again!

Chris

 

My '04 'Vette came with an inflation kit to go with the run-flats. It's a pump and a plastic bottle of Slime. I understand Slime won't hurt the tires.

 

Slime won't hurt the tires, but it can (sometimes does sometimes doesn't) hurt the air pressure sensor. I looked at it as a cost of the option with my BMW. The cost of non-RFT's versus RFT's would easily make up for replacing the sensors. On the BMW they were $50 each. I would guess that it is similar on the SL.

 

I checked with "Slime", and according to their sales guy, the current generation of pressure sensors, and the current generation of Slime, is supposed to be compatible. Theoretically, there is supposed to be no damage to the sensors if Slime is applied to the tire.

Theoretically....

And I'm still hoping that my two Slime Kits will die a natural death thru age related non-use decay....

But even if the sensors did need to be replaced after a "Slime" incident, the ride and handling improvement of the Michelin PS tires over the Bridgestone Potenza "run flats" is completely worth it. No question whatsoever!

Chris

 

Hi

New here but need your input I am based in the UK.

I have a 2013 SL63 which MB UK tell me cannot be fitted with Run Flats.

Reading your posts in seems that you can order SL63 in the US with Run Flats.

Is this corrrect??

If so time to ask questions from MB customer services in the UK as to why they cannot be fitted in the UK when they can elsewhere (I think you can spec them in Australia as well)

Thanks for your help

 

There might be a difficulty in the terminology. The "run flat" MB approved tires have "MOE" on the tire sidewall (if I remember correctly). It partially stands for something like "Operation Extended".

The other thing to check is to see what the MB UK people do for a "flat tire incident"? Do they provide a "TireFit" kit with the car??

The TireFit kit is a small 12VDC air compressor, a container of tire sealant, and a mechanism to inject the sealant thru the valve stem, and into the flat tire.

The MB "TireFit" kit is around $90 USD. You can purchase the same thing from eBay for less than half that.

Hope this helps,

Chris

 

In the US, the SL63 doesn't come with run flats either. If I recall you have the forged wheels (19" front/20" rears) so you can't fit RFT's. You could if you would have had the standard 19" AMG wheel setup on your SL.

I have the Michelin Super Pilot Sports, stock are the Pilot Sport 3's. Both are worlds better than the RFT's.
I wouldn't bother if I were you...

 

Run flats will always be a rougher ride. The sidewalls are almost 3 times thicker. They don't flex. The flex is what gives you the softer ride. Changing tires would be good idea after they wear down if you want the softest ride.

 

I have a question on the Run Flat tires that come standard with the SL550 with the Sport Wheel Package. I have read on this thread and heard elsewhere that the tires are very expensive to replace.

Do you recommend then to get the Wheel/Tire Warranty (I know I'm not using the correct term here) or just pay for new tires when needed ?

How long (miles) are the tires expected to last with easy driving ? I have heard the rear tires will need replacing before the front ones.

I am wondering if there is anything special about these tires ? I also have run flats on my BMW X5. I am at nearly 37k miles on those, and they now need replacing. No issued with them so far.

Are the tires/wheels special to the SL that they would need to be replaced quicker or more susceptible to damage ?

Thanks for your help.

 

My experience in general with the SL's is that the rear tires wear out much faster than the front. My last SL only got 13k on the rears. Those were not run-flats, however.

Run flats are more expensive by about 20% than regular tires.

I now have 5k on the run-flats on the 2013 SL. Can't yet give you an indication of how long they will last. I certainly hope they will go longer than 13k!