amf77

Our 2018 E class has run flat tires. This is the first vehicle I have had with run flat tires, so when we purchased the car, I was concerned that there was no spare tire.

Yesterday, my wife took our E class, to the supermarket. On the way over, she called me and stated that the display on the dashboard shows a pictograph displaying the chassis and 4 tires. Illustrated was the tire pressure and tire temperature of all four tires. One of the rear tires showed pressure of 31 psi, and it was shown in red. Both front tires had originally been set to 37 psi and both back tires had originally been set to 39 psi. The rear tire, which had the puncture, was shown in red, and showed 31 psi. on the pictograph. I swapped cars with her and drove her car home. All during the 3 mile trip home, the tire pressure of the punctured tire stayed at 31 and 32 psi. (probably heat related variance) The point being is that when a run flat tire is punctured, it is still apparently safe to drive, and it doesn't ruin the tire, or the wheel. Bringing the car home, allowed me the opportunity for a look at the tire. I first checked tire pressure to confirm what I saw on the pictograph......confirmed. Then I jacked up the car and removed the wheel/tire. This is the heaviest wheel/tire I have had on a car.....so much for weight savings., It did work as designed though. I found where the puncture was, and marked the spot. (the puncture was very small, making me believe that the puncture could have happened some time in the past??). I then took the wheel/tire to a tire shop for repair. The tire shop repair procedure is the same as any other tire; ie. take the tire off the wheel and put a patch on the inside of the tire.

My concern is: if we we are on a trip somewhere, and we are in "timbuktu".....with a tire puncture and nothing nearby for repair......with no spare, what to do. (Fortunately, we belong to AAA and I guess they would come out and "plug" the tire?) (From what I have read, AAA is a better choice than the Mercedes assist button?).

I thought I would share this experience, as I am sure there are others who have not had experience with Mercedes (Pirelli) run flat tires. Hope this is helpful.

rbrylaw

Wheel and tire insurance is a good thing with these puppies! On my C300 with Pirelli Run Flats, I managed to get screws in two tires. The nice thing is you can drive on them safely for up to 50 - 60 miles. Fortunately, both times it happened I was close to my MB Dealer. If I was in Timbuktu, Mercedes offers the same service as AAA and you don't have to pay for it, so you might what to think about continuing to pay for a service you get for free with your car. Also, Run Flats are theoretically NOT supposed to be plugged. I imagine some do that, but if your tire is punctured, it's supposed to be replaced with a new tire.

Yuille36

This was a big concern of mine as well, as most manufacturers these days are going to route, with run flat tires and no spare. They tell us that we can drive on these tires for at least 150 miles, at slower speeds.
Or until we can have the tire looked at. Mercedes along with BMW will not simply plug the tire, they will replace it on inspection. I had to replace my tire once since purchasing my vehicle, and to be totally honest, I wasn't concerned one bit. At first, I was just going to have the tire plugged, then I remembered that I have the wheel & tire warranty. And they replaced it, no questions asked. So, if I was you, I wouldn't be overall concerned about this.

rbrylaw

Agree 100%. In real life, it's just not an issue and actually works really well. The advantage is you just won't have a blowout, which is infinitely more dangerous and can cause someone to have an accident.

superangrypenguin

We define the word "well" differently.

ua549

My issue with RFT is that tire dealers in my area do not stock RFT's. One must go to an MB dealer to get a replacement. That's OK 9-5 M-F, but after that the option is to park it, leave it and arrange alternate transportation. MB road service does not carry those tires either. BTDT

704set

I caught a screw in my RFT earlier this year. The tire dealer said the puncture was too close to the edge to be repaired. I could not find anyone who sold the tire except for a Mercedes Benz dealer. Just hope when you are in Timbuktu a MB dealer is within 150 miles.

JTK44

Couple of things:

Run flats eliminate the spare which saves weight and increases fuel economy -imo, the main reason for the RF.

I drive to Vermont to ski and wonder what I would do if I got up in the morning and the tire was flat: Not a pretty story:

I am in southern Vermont, Ludlow. I had a BMW 535 iXdrive with RF tires. If I had a flat, I was told to call BMW service. The nearest dealer was in Burlington, VT 150 miles to the north. They would send a truck to flat bed my car and hopefully return it to me within two days. Even though there is a large Chevy dealer in Ludlow they did not carry RF. Ditto tire dealers in Rutland, some 40 miles away.

This problem was solved with my present 2016 E350 which has a spare.

Now the problem is back again with my E450:

Tire and wheel insurance only helps with payment!

Tire and wheel insurance does not help if you have to wait several days for a RF replacement!

With the 2019 BMW 540i xDrive you can order a spare. Unfortunately, Mercedes does not give you that option.

So if you get a flat in "smallville, USA" you are plain dumb out of luck! (and me too!)

jumpman726

One thing that I didn't see anybody mention is that a RFT is more prone to getting a puncture, excessive road noise, and faster tread wear than a standard tire because of the harder compound and stiffer sidewalls.

jumpman726

RFTs are heavier than a standard tire, so I don't think there is any weight savings by not having a spare. The BMW 540i offers a spare option, but that option reduces your trunk space by about 30% to make room for the spare underneath.

JTK44

I believe by 17%, but it could be 30%. For local driving you can take the spare out and get full use of the trunk.

Having a spare in your trunk when you go to "Smallville, USA" is nice insurance.

It is not just the weight of the tire, but the elimination of the wheel, jack, etc. all to save weight to increase EPA estimates. This more than offsets the additional weight of the RF vs. ordinary tires.

see: https://cars.usnews.com/cars-trucks/...-pros-and-cons

amf77

Interesting.........I agree that I would not want a tire....run flat or otherwise.....plugged. What I was thinking was that perhaps the AAA vehicle in "timbuktu might carry a "plug kit" and compressor to be able to at least get us going if we had to travel more than the distance the "flat" run flat would get us, with low or no air pressure in it....to a place where we could get the tire removed and properly patched.....assuming the tire is salvageable for safe use. I too don't see where the run flat tire saves any weight over having a spare.......and if the run flat is damaged in any other area aside from where the tread is....all bets are off as the flat run flat can't be fixed. And if the tire is flat, there would probably be trouble getting the car onto a flat bed truck without scraping the bottom of the car bumper. I see this having the potential of being a real "pita".

JTK44

Perhaps a call to Mercedes to ask them what happens when you have a flat in a RF, are in "Smallville, USA" and there is neither a tire shop that carries replacement RF nor a Mercedes dealer within 100 miles, is in order.

I suspect that they might just say buy a new tire as ordinary tiers are compatible with the wheels of run flat tires.

See: https://blog.tirerack.com/blog/bens-...at-wheelswheel and tire -


Here is another link to the the "pros and cons" of run flat tires: https://www.edmunds.com/driving-tips...-a-primer.html

ua549

The difference between RFT's and non-RFT's on my car with 245/45R18 Pirelli tires is 4 pounds per tire. So RFT tires weigh 28 x 4 = 112 lbs and non-RFT tires weigh 24 x 4 = 96 lbs. Then one must add the weight of an additional tire and wheel. I don't know exactly how much a wheel weight, but I estimate it is about 25 pounds. Thus the RFT weight is about 212 pounds and the non-RFT alternative with spare is 245 pounds. RFT saves about 33 pounds.

JTK44

Plus, the jack, bolts and lug nuts to hold the tire/wheel securely in the trunk. another 10 to 15 pounds, total 43/48 lbs.

Of course I do not know how that weight effects EPA gas ratings, but we do hear about manufacturers "Bragging" and making a big deal about using aluminum for example to save 100 lbs.

So savings 43 to 48 lbs. might be meaningful.

2thfxr

It is all about weight reduction due to CAFE mileage ratings that keep increasing mandated MPG. We have plastic headlight lens instead of glass because of this and look at the fogging problems that has created.The same goes for aluminum body panels istead of steel, it is all about weight savings no matter how small. Some Porsche 911's have a Weissach package that costs, get this, $31,000 to save 40 pounds!

lkfoster

When we get our E53 Coupe I'm getting a compressor and sealant kit. The wife had a blowout in our old C55 two hours out of Las Vegas in BFE Nevada at 2am and all MB Roadside Assistance told her that "we can't find you, call a tow truck". She wasn't impressed. She wound up changing the tire herself.

cetialpha5

I'm surprised no one mentioned it, but Pirelli run flats have a road hazard warranty. Contact the dealer or Pirelli and have that tire replaced. They don't recommend any flat repair to their run flat tires. Other tire makers like Goodyear are the same, but they don't offer any road hazard warranty.

https://www.pirelli.com/tires/en-us/.../tire-warranty

I think in the old threads, there's a lot of hate for run flat tires, lots of people switch them out for regular tires as they feel they're smoother, quieter tires.

ua549

That Pirelli warranty does not apply to OEM tires.

fleuger99

My BMW X5 came with summer performance RF tires (I have 20" staggered wheels/tires). They are noisy, harsh and wear out in 18K -20K miles. At 10K miles I replaced them with non RF all-season performance tires and they are so quiet, and ride much better. Instead of getting a spare tire I purchased a tire seal/pump kit from BMW which will work in the event I'm in the middle of no where and get a flat.

I'm not sure about Mercedes-Benz dealers but BMW dealers will not repair/plug a RF tire, they require you to purchase a new one.

fleuger99

I think it's more about reducing their costs than reducing weight.

ua549

Actually RFT's cost more than standard tires by a large margin. On tirerack.com the difference for the tires on my car amount to over $60 per tire. The total cost for 5 tires plus a jack and wrench about the same as 4 RFT's. The manufacturer's savings comes in the form of reduced weight to assist in meeting CAFE standards. Not included is cost reduction of the design due to the lower weight and simpler structure (no spare tire storage).

fleuger99

No manufacturer is paying retail for their tires when they sell tens of thousands of cars. So comparing our costs to their's is not realistic. I don't know about all cars but my 2018 X5 has the tire storage space under the cargo floor so it's designed to still carry a spare and BMW offers that as an option package. Spare wheel with tire, jack and tools for $399 I believe. To me saving $399 per vehicle they sell is a significant cost savings.

cetialpha5

Yes it does. Read the road hazard section of the warranty in the link above. When they come on a new car, they go by the purchase date of the vehicle. I believe in the old messages, someone else got theirs replaced under warranty.

ua549

I went through the process when my car was a few days old. Pirelli denied coverage so the dealer/MBUSA replaced the tire.