Run Flat Tires Test

We put BMW run-flat tires to the test and give them a thumbs-down

Run-Flat tires are standard on most BMWs. Why we think you should avoid them, and a selection of other opinions on the subject.

We recently had an unplanned opportunity to put run flat tires to the test. Our impromptu test vehicle was a 2013 BMW X3 xDrive 28i crossover. During a Sunday trip to a park we had a puncture that gave us the chance to see how a run flat preforms while driving deflated, as well as explore the repair/replacement options and see how they might compare to other road hazard management options like a full size spare or temporary spare. We learned quite a bit from the experience and hope you find this information helpful if you’re considering a vehicle with run-flat tires.

We first noticed the flat when we re-entered the vehicle because the car told us the front left tire was low via the information screen. A system like this is now government-mandated on all modern cars. Hoping it was just low, and not completely flat, we looked at it closely and could see it was definitely flat. Moving the car slowly with the window down resulted in the crunchy sound of a flat tire and the feeling was noticeably wiggly and sloppy. The sound was so much of a concern we opted to call BMW via the car’s SOS button. After reading, re-reading, and then re-reading the VIN about 6 times to the BMW representative after they already knew us from our name and model number, not to mention the account we called from (frustrating), the person at the other end told us to ignore the sounds and feelings and drive it under 50 miles, and under 50 miles per hour, to wherever we wanted to go. She said as long as we didn’t smell burning rubber not to worry. Off we went.

Run flat tires work by using a much more robust sidewall construction. The stiffer sidewall is able to support the uninflated tire temporarily. However, driving on the tire without air pressure destroys it. In their marketing, makers of run flats try to compare older tire technology to their new, lower-profile tires with the stiffened sidewalls, and claim some safety benefits. We are skeptical. Blow-outs and complete tire failures on new, lower-profile, modern tires (not run-flats) are extremely rare.

My passenger input in a Nav course home (14 miles) that did not use freeways. The excellent BMW Nav system made this pretty easy to do, although we did have to wait a few minutes while it would only display a warning message about the tire. As we drove my passenger also called the BMW dealership the car is serviced at. To its credit the dealership did answer, but since it was Sunday, they could not help us in any way. Take note of that. Next my passenger looked up the local tire place she services her Honda Fit. It was also closed. We looked for a third place along our route home, also closed. Our plan became, “let’s get it home and then deal with the issue Monday morning.”

Driving On a Run-Flat Tire
The feel while driving the car with the deflated run-flat was just what one might expect. Sloppy, pulling to the side of the flat, and pretty apparent something major was up. It would be very hard to ignore this even if the dash wasn’t constantly telling us about the issue. We looked in the owner’s manual, which is the size of three Korans, and in the section under flat tires it had a note about the 50/50 miles driving, and that was pretty much it. I mainly wanted to know if I should try to re-inflate the tire. I figured that would help, but I wanted to also make sure it would not cause a rupture of the sidewall. I saw a gas station with an air hose and pulled in. I checked the pressure and it was “0.” I pumped it up to 45 psi. Driving off the car felt dramatically better, but still slightly odd. 4 miles later we were again flat. I found a second station with a lousy air hose and put in about 20 psi. Again it felt better than flat.

The sounds of the car on the flat were the most alarming. It sounds like rubber crunching and is pretty loud. I ignored it. Keeping our speed steady and slow (about the 30 to 35 MPH speed limit) we got the car home OK.

Dealing With the Run-Flat Repair
The BMW dealer was much farther away than the local tire chains, so a local place became our repair plan. Travelling to the BMW dealer would have taken us close to our limit of 50 miles and it was also out of the way for our Monday work plans. Calling around we found that a local Town Fair Tire chain only 6 miles away had the ability to replace our Pirelli Cinturato P7 245/50/18 run flat. Here is the first point we wish to make. This was a puncture from a nail in the middle of the tread. If we had a spare we could have easily put on the spare, driven home and then to a tire place to have the puncture repaired properly (inside patch/plug, tire-off method). That would have either been free, or done for a nominal fee of less than $50. Instead, we are now looking at replacing a tire.

Town Fair and also Tire Rack, which we looked at as a reference, had pretty much the same price for the rubber. The tire itself costs about $350. Let’s stop here for a moment. We compared a best seller, non-run-flat Michelin of the exact same size and specs, and it cost only $200. So the run flat, in addition to requiring a replacement instead of repair, is also dramatically more expensive. Remember too that the closest tire place we tried does not handle run-flats at all.

I used my portable pump to pump up the tire before setting out the 8 miles back to the tire store. The ride there was the same as my previous trip.

Comparison of Run-Flat to Other Options
My 2007 Highlander Sport could have been the car taken that day. It is exactly the same size as the X3, but with more interior room and more cargo room. That vehicle has a full-size matching spare on a matching rim. Had we been in that vehicle, my matching spare would have gone on, I could have thrown the flat tire in the back, or put it in the spare tire well under the rear of the car, and then had it repaired at my leisure for less than $50. Or I could have replaced it. I just bought tires for that car and they cost $130 each including tax. This run-flat scheme is supposed to be progress?

Another alternative would have been a temporary spare. This is the direction most manufactures are now going with most models. At least with this option I would have probably saved the cost of the new tire. Also, had we ripped a side wall from hitting a road defect, the run-flat would not have been an option and we would have had to be towed twice. Once home, and then again to the tire place the next work day.

Why Do Manufacturers Use Run Flats?
Manufacturers claim that run-flats save both space and weight. Baloney. I checked the specs of the Pirelli run-flat. Its weight is 33 pounds. The non-flat Michelin with the same specs is 26 pounds. That means a temporary spare weighing around 28 pounds would have been a zero-weight added solution compared to the run-flats. Also, a car this size with its massive cargo area can afford the small wafer of a temporary spare, or even a full size spare, as my Highlander proves.

Conclusion – Avoid Run-Flat Tires
Manufacturers are doing everything in their power to save money, increase their profits, and to do the best they possibly can on the EPA mileage estimation test. That is understandable. However, it is hard to justify this move away from customer convenience and customer value in terms of affordable tires and repair options. This author’s opinion is that run-flat tires, and models that use them exclusively, should be avoided by consumers. We are not alone. J.D. Power surveyed customers about tires and found that customers scored cars with run-flats significantly lower than those with conventional tires. Some customers who bought run-flat tires have even sued BMW in a successful class action suit.

Other Sources of Information:
Autoguide – Why You Should or Should Not Buy Run-Flat Tires
Jalopnik – Everyone Hates Run Flat Tires
Consumer Reports - My luxurious BMW 750Li run-flat nightmare
BMW's Run-Flat page

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Comments

Thanks, John. I personally hate run-flats and have spare tires for all of our vehicles. Even if they do work, we are often more than 50 freeway miles from home anyway.
This was really interesting. I didn't even know such tires existed. I wonder if they were created for people who don't know how to change a tire? Maybe BMW owners don't know how.
The new BMW i3 has no run flats, has no spare of any kind, and uses tires that are exclusive to only it. I wish I lived in a world where that made any sense whatsoever.
I thought that was a very interesting and useful article. Couple of counter points however, I have noticed that some people will just drive their car to the nearest garage whether they are run flat or not. Perhaps these folks might benefit from having a run flat tire. I recently noticed that the car in front had a flat tire. So at the next traffic lights I jumped out and told the senior citizen lady that she had a problem. Oh for Christ's sake she said, and drove off. It was clear to me she was not going to stop on the road and change the wheel. Also once on a dark rainy night on a busy highway my tire went and there was no way I was going to stop right away for fear of being hit.hit. So I had to drive a mile or so to find a safe place to pull off and change the wheel; but that tire was a goner anyway. Perhaps a run flat would have survived the experience. What do you think?
Good point. Yes, run-flats are better for people that will drive on and on with no tire pressure. However, I too have driven short distances on a flat and as far as I know all modern tires will allow a person to drive slowly for about the distance of a highway exit before coming off the rim or cutting through it. My understanding form the BMW literature is that if one drives at all on a run-flat tire, it needs to be replaced, so there is no real financial upside I can see.
I have a 2011 X3 that I have driven for 40k miles. At first I didn't like the idea of run flats but three years later I have a different view. 1) At high highway speeds 80 MPH I take comfort in knowing if the tire blows out I'm not going to lose control of the vehicle and find it provides confidence while driving. 2) I'm at ease knowing when my wife is driving alone that she can make it home or to a safe location to get assistance. A real concern with her driving at night on the local express ways. 3) I have had three tires punctured and replaced but purchased a warranty that paid for the replacements. I have more than recovered the cost of the warranty and have three more years of free coverage! 4) I have had to put a spare on a car before on a road trip only to have a second tire go out 300 miles further down the road and been totally stranded needing a tow. The run flats avoid this scenario. Are they a perfect solution ...not by a long shot but as with all things there are trade offs. For me I'm sold. SO much so that I would likely trade out regular tires for run flats if my next vehicle din't have them.
Kevin, you make some good points and I appreciate you expanding on the story. BMW has done its best to make people think its run-flats (really the tire makers' run flats) are safer on the highway in some failure situations. Believe what you like. On its fastest cars (M series) BMW does NOT use run-flats. - With regard to your spare scenario, a run flat would have failed at 50 miles, rather than the 300 you point to according to BMW and the tire information. So I don't get the point. - If you ever do decide to try run-flats on a car that was not designed for them, read up first. The damper (shock absorber) and spring rates on a car design for run flats is not the same as cars that are designed for conventional modern tires. You seem to be all about safety, so you may want to be aware of that. - - Finally, BMW's newest model, the i3, does not use run-flats and has no spare. The tires are also a size only it uses. I have no clue how that makes sense in a world where people like me and you plan carefully ahead for things like punctures and highway damage at high speed, or for being safe in places we don't want to be stranded with a puncture. So my way of seeing this is that in BMW's newest model your wife would not be protected in either scenario one or two, and in scenario 3 and 4 you would have to wait three times for a tow and then skip your road trip.
If you look at video's of test done with run flats vs regular tires in emergency maneuver situations I think the safety advantages are compelling and speak for themselves. I particularly like the one done by motor week in 2009 with a BMW 3 series available on YouTube.
Google Fifth Gear Run Flat Tire Test. The video provides a compelling endorsement for the safety value and benefits of run flat tech on BMW's.
John...Just as an FYI..the M series does use run flats. I bout my new M series in August and it has run flats on it. Regardless...They are pricey, not quite as a smooth ride. No 50 repair job on these babies either. But it is a personal choice. I like them. Don't have to worry about changing a tire on a busy highway and when they blow you don't even feel it...I actually blew one last night. Yes my wallet will be lighter but for me they are perfect.
Congrats on owning an M. I saw the new M4 this week and it looked awesome. Actually, on an M car I can understand the use of run-flats. They are heavier than regular tires, which is a negative on a car that puts so much focus on weight savings, but I can understand it. On a passenger car I don't think they make good sense. I understand you got a "blow-out." To me a blow out is when a tire depressurizes instantly due to major damage (from failure or from striking something) and the tire comes apart partially or completely. A puncture or a "flat tire" is when the tire loses pressure due to a hole or a foreign object embedded in it. Blow outs simply do not happen with modern radial, low profile tires that are properly maintained. They are incredibly rare. Punctures do occur and the mandated TPMS system will alert a driver of the drop in pressure. One can always choose to then slowly exit the highway via the breakdown lane. It may destroy the regular tire, but run flats driven flat are also destroyed. The videos I have seen do not convince me of a needed safety advantage. Road debris can also tear sidewalls on run-flats, so they are not a guarantee that if something large is struck they won't also be un-drivable.
I have been using Bridgestone run-flats on two 3 series BMWs for just on 12 years now and I think they are fantastic. I currently have 225/35R19 88Y BS S001 RRFT on the front and 255/30R19 91Y BS S001 RRFT on the rear. I have never had a flat and the noise does not bother me. I drive on both sealed and non sealed roads and as my wife would say, tend to push the limits of the car a bit too much now and then. I find that most negative comments come from motor journalists/drivers who have still got their mind completely locked into must having a spare in the boot. I get around 70000 kms before replacing the tires. I carry two good tyre pressure gauges and always check the pressures every time I fill up with petrol. When you are spending $500/tyre you need to make sure you look after them. I suggest anyone thinking of buying them talks to the manufacturers (both car and tyres) before taking for granted comments written by someone who may have other priorities or pet hates. Happy driving folks.
Daryl makes a couple good points that I neglected to add in the story. I do spend a lot of time on BMW run-flats and they are exceptionally good with regard to noise, durability, and general handling characteristics (though that is very subjective). Thanks Darly, for adding some good perspective.
I have a new x1 with run-flat tires with less than 1500 miles. Today my husband drove over a small screw while parallel parking on a street. I was standing on the curb and witnessed/heard the tire instantly deflate to point where it was very very visibly low. The screw is in the tread. It is Sunday and the nearby BMW dealership was open. We called to let them know we were bringing it in, and to ask the best way to get there via backroads. We explained what happened and he said we should not attempt to drive on the tire with it that visibly low as we risked damaging the rim or wheel well or whatever he said. So we called BMW assist and they sent a tow truck. The guy from the dealership called back and recommended we instead go to a local tire shop, such as a nearby firestone which he confirmed was open to see if they could repair it. He explained that not only was the BMW service center not open, they would not repair only replace. While waiting for the tow truck we called firestone, who said our run flat tire would likely need to replaced. He said he would look at it, but it probably could not be repaired (again simple tread puncture). Further, he said that even if he thought it could be repaired, he would not work on it without BMW signing a liability waiver. He said they did not have these type of tires in stock so he would have to order it if needed. We could not take the chance of having the tow truck take us there and then being stranded for however long it took to order a tire, so we opted for a tow to BMW. My car sits there now until tomorrow when the service center opens and they can call me. I am outraged that I have a simple puncture and my new car had to be towed to the dealership. They did give me a loaner car thankfully. This is apparently not supposed to happen to a run flat tire, but it did, and instantly. My question is am I missing something? Could this be a defective tire? Is this something that should be covered by any warranty? I find it outrageous that I had to have my car towed because of a simple puncture. I had no other reasonable options than to have it towed to BMW where I am guaranteed to need to buy a new tire. Even if the RFT had worked as advertised, it apparently would still need to be replaced. That seems absurd. Based on my brief research some places would patch/plug a RFT, but now it seems they want BMW to sign a liability waiver to do so. This was confirmed from what the Firestone guy said. Any help is appreciated.
I really feel for you as I think you have been given a bit of a run around. The following statement comes from the BMW website. "How long can I drive on a deflated Run-flat Tyre? This depends on the amount of people travelling in the vehicle and if the boot is fully loaded: • With low loads, one or two persons without luggage: Approximately 240 kilometres at a maximum speed of 80km/h • With moderate loads, two persons with full luggage or four persons without luggage: Approximately 145 kilometres at a maximum speed of 80km/h • With a full load, while towing a trailer or four persons or more with full luggage: Approximately 48 kilometres at a maximum speed of 80km/h" Based on the above, you should have been able to drive to your dealer. As for repairs. In the past, all damaged RFT's had to be replaced but some makers are changing that. I have Bridgestone S001 on my 3 series and they can be repaired (nails and screws type of damage). Not sure what others are doing.
Our BMW 650i has just had its SIXTEENTH tire replaced. It is a 2012 model and we have driven it a total of 13,000 miles. We drive in Manhattan and back and forth on the Long Island Expressway -- nothing so exotic. This $109,000 car is rendered completely unreliable by BMW's "commitment" to run-flats. Try as I might, I cannot see the logic in any of this.
Don't you see the huge safety advantages and the incredible weight and space savings as a big improvement in your life? How can you be so blind? My local tire repair shop has told me similar stories.
Sarcasm is that was not obvious.
Rosemary, WOW. I am surprised that you either kept the car or did not change to NON run flat tires after going through only 5 tires. Something is definitely wrong. Has anyone come close to working out why you have this problem. I must admit though that I had a bigger choke when I saw the cost of your 650i. A new 650i coupe here in Melbourne, Australia has a drive away price of US$232,755 whereas a 2012 650i can be bought for US$156,00. I hope the cost of tires in NY is in proportion to the cost out here. Mine cost approx US$470 per tire fitted. Good luck.
Daryl, As to why we haven't replaced them...our BMW dealer told us that if we replaced the tires with non-run-flats, we would invalidate our 3-year warranty. The streets in the NYC tri-area are very bad after our disastrous winter (and failed government), and the dealerships just blame it on that. However, when we took this car in 2012, the salesman INSISTED that we buy tire insurance. He was so adamant that we did, and this has covered the cost of towing and tire replacements, which would have had a retail cost of more than US$8,000 by now. Still, it doesn't compensate us for the time it takes to get these tires (we often have to leave the car for 3 - 4 days), and it surely doesn't make up for being left on dark roadsides awaiting the tow man, who invariably says that he "tows a lot of these BMWs with run-flats." Worse still, the RFTs run so hard that we've also had to replace the front suspension! We've been patient because we do love the car...but our affection has been defeated by these tires.