Indophile

I have an S550 4Matic (2017) with Michelin 275/40R19 run-flat tires. There are two bubbles in the sidewall of one of my tires. The dealer told me not to worry about it. However, I went to a tire shop to patch a nail in a different tire. He saw the bulge and told me it was unsafe to drive. He also told me I would have to buy four tires - not just one. And finally, he said the wheels could not be rotated because the front and rear wheels are different specs.

Whom do I believe? The dealer or the tire guy?

rediesel

Both - Neither

Technically bubbles should be replaced. That said I get so many that I replace them if the tire is covered under road hazard warranty and I'll only have to pay for mount and balance, or if it's starting to get worn. I have a bubbled tire on my wife's E63 wagon, but it's small and the tire is practically new (It was a replacement under road hazard so I can't get a free replacement). My dealer just put a single tire on that car last month to replace another that is worn. I think the tire shop want to sell you tires. I used to go to a local tire shop for all my tires, but my dealer has become more competitive on price, and if I get MO (mercedes) tires and they develop a bubble or sidewall puncture they replace them for free within a certain time period or tread wear, and I've gotten several replaced this way. If your tires are staggard they cannot be rotated.

as.thompson

I had my 2016 S550 coupe in the MBZ shop for routine service 2 weeks ago and the tech noted a bubble in the sidewall of one of my tires. I was initially concerned but when he showed it to me I could hardly see it. Even now, I have a difficult time finding it. The shop said to just watch it to see if it gets worse but didn't say it should be replaced.

Years ago I had a bit of trouble with bubbles in the tread on a series of Bridgestone tires on my Porsche 911. That resulted in vibration at all but the slowest speeds. Switching to Michelins cured that problem.

Indophile

Thanks ReDIesel and as.thompson!
I spoke to the dealer again, and he suggested just watching it - especially on long trips where the tire can get overheated. On the long trips, if I take a break once in a while, it should be ok since it will give a chance for the tires to cool. The tires are run-flats, so no blowout is likely. He said I could ride it out until the tires are due to be replaced (maybe in another 5000 miles). I called Costco Tire, and they suggested the same thing - although they were slightly stronger in recommending changing the tire.

Streamliner

Man, I cannot believe this discussion! If you have a bubble in a tire, replace it IMMEDIATELY! Thinking about driving on such a tire, for any distance, to me, is just NUTS! You are taking a huge risk, as it is just a matter of time before the bubble blows and that amount of time may just be in the next minute. In the case of W222 cars, we are talking about very heavy cars that are putting a tremendous amount of pressure on the tires. In addition, these are very expensive cars and I just can’t imagine that anyone driving one cannot easily afford new tires. GEEZE! Whatever it takes, go get new, high quality tires RIGHT NOW!

Indophile

Streamliner, not being an expert - I am going by both the dealer and Costco saying that it was an acceptable risk since they are run-flats and will not blow out. I do have a long drive this week, and the replacement tires will take several days to deliver.

Streamliner

Well, we all make the best decisions we can. The first one I would make, is to dump the run flats and get some great conventional tires. Then, I’d put a jack & compact spare in the trunk. Oh, wait! I’ve already made and acted on those decisions! Sorry. And, if and when I ever need one tire, they are readily available and no need to buy multiples.

Seriously though, believe me when I say that that run flat tires can blow out or become shredded by road hazards. Happens every day. Wishing you a safe trip.

Fastbuck

Not quite exactly the same scenario but a timely warning nonetheless.


https://www.thedrive.com/news/28369/...s-benz-s-class

Streamliner

Another comment: Tires are SO very important to ride quality, handling and, above all, safety, that on a 3 year, 36,000 mile lease, I replace the tires at 18,000 miles. You see, I prefer using the first half of a tire’s life, not the last half. In addition, I feel that based on what they provide, tires are downright CHEAP! I run 18” Bridgestone Turanza Serenity Plus tires on my S560 and have had several sets on previous cars. They are very quiet, very smooth riding, handle nicely and at about $220.00 each, I feel they are a true bargain. And, just so you don’t think I throw money away, I sell the old ones on Craigslist, usually getting $200.00 or so for the set.

seamus2154

RF's do NOT blow out. They lose pressure. You can literally drive with a chunk missing from the sidewall. So having a bubble would cause me to keep it in mind and watch it. If it gets compromised, I would not continue driving unless it was to get to a safe place or tire shop. Some of the advice is as if it were a regular tire.......?

If it were a regular tire, I would not risk a blowout and would painfully replace it.....

Streamliner

I believe that is the fact most of the time, but if you look around on the web, there are stories of RFT blowing out.

seamus2154

Define blowout?
A blowout as known to a regular tire is a catastrophic loss off pressure or damage causing it. When that happens to a "regular tire" you have lost the structure of the tire, hit the rim, or tire can come off the rim and bead. It is a serious event, many times causing loss of control of the vehicle. That is NOT the case with a RF. It is designed NOT to do that. The bead stays intact and it literally supports the vehicle by the side wall compromised or not.
https://f30.bimmerpost.com/forums/sh....php?t=1398649

Mitch Alsup

So much wackiness........

The tire with the bulge has become unsafe; you can push your luck for a while at some liability to your car.
You can rotate different width tires L<->R just fine
When you get tires for ANY high performance vehicle, you should get 4 tires.
.....Unless the 2 tires you are not replacing have a date code within 3 months of the tires you are replacing them with.

Detailingdoc

Whats the basis for within 3 months of date code.

Running Rwd the back tires wear faster than the fronts. Why do i need to replace fronts if still more than acceptable tread.
I have heard of Avs have in the past reolaced opposite side esp on staggered setups if you replace one.

Mitch Alsup

When you put on tires with the same date code, you are assured that the tires on the front and back are made the same way and use the same rubber compounds--and thus give predictable traction.

When you change one tire only, that new tire will be::
a) larger in diameter causing one suspension corner to be more heavily weighted than the others
b) newer in rubber compound--possibly with greater traction or possibly with lesser traction.
c) causing alignment issues--pulls to the L/R ; brakes to the L/R, accelerates to the L/R
b) and point traction issues-- one tire brakes to skid earlier than the others or later than the others
leading to lack of confidence in the road manners of the car.

When you change both tires on an axel:
you get ride of 1/2 of the above, but keep the other half.

Basically, if you are going to push the traction envelope (cornering, braking, acceleration) and you have more than 300 HP; you should buy tires in sets of 4.
I went to the trouble of setting up my Ferrari such that all 4 tires go bald within 100 miles of each other (10K mile tire life).

joeyb1000

If it were me, I'd agree with Streamliner and buy 4 new tires. But, I wouldn't call it an emergency.