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BMW 3-Series Run Flat Tires

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Comments

  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I bought a MINI because it was such fun to drive. I threw away the RFTs immediately (and good riddance to noise and foul-handling) and fixed as many of the factory defects as fast as the aftermarket could develop the remedies. It wasn't the perfect car, but I worked to make it better. Had I wanted a trouble-free, worry free transportation module, we all know where to go for that.
  • busirisbusiris Member Posts: 3,490
    edited July 2011
    I certainly understand your motives in swapping out the RFT's. The originals on my wife's MINI were also noisy, but the new RFT's she installed in late 2010 appear to be much quieter. I will say again... in a perfect world, a buyer would have the factory option of RFT's or GFT's.

    I also agree with your opinion of the car. No, it isn't perfect, but then again, anyone who buys a German-made vehicle with the intention of keeping it several years, while at the same time expecting low maintenance costs is, shall we say, a bit delusional...or at least, "uneducated" on German vehicles.

    For those who abhor RFT's, they have the option of going the M3 route by using GFT's and carrying a small tire repair/inflation pump kit. No, its not as good as a spare, but in most cases will be acceptable.

    What really cracks me up, though, is the few folks who think BMW (or any carmaker, for that matter) should cater to their specific desires, while disregarding the general market's desires.

    When I bought my Z4 coupe in 2007, I remember asking my sales rep why there were so few manual BMW's on the lot. His response was that manuals didn't sell, but automatics did sell. I jokingly mentioned that if all the cars they had on the lot were manuals, then they might sell more of them. His response: There are plenty of other competitors in the car business.

    You get the idea.

    Another one of his observartions was that, in his experience, most of these same folks that compain about BMW forgetting its roots usually don't buy new cars, but used ones. If they do spring for a new model, its usually "option-lean", which means less $$$ for the rep and the dealership.
  • busirisbusiris Member Posts: 3,490
    Condensed from the Greenville News (Greenville, SC):

    BMW stated Thursday that it set sales records for both the month and the first half of the year, with volume up 137,000 units compared with last year's production numbers, to 833,366 vehicles (20% higher than the first 6 months of last year).

    Last month BMW sold 134,432 BMW brand vehicles worldwide, with BMW brand sales totalling 689,861 (17.8% higher than last year). MINI and Rolls-Royce had double-digit gains both for June and the first half of the year.

    Seems to me that all of these buyers couldn't be in the dark about RFT's. Surely, some of them are intelligent enough to know what type of tire their car has mounted on its rims.

    Manufacturers produce the products that sell, or they would be out of business in short order.... especially in a competitive environment as automobile production.

    Whether or not one likes or hates RFT's, its pretty clear that BMW is set on its RFT offerings and isn't going to change directions in that regard any time soon...
  • boston303boston303 Member Posts: 35
    The sheep rule. Form overcomes function. I simply have no interest in such an over rated car. My current 3 series is a total disappointment. As I do advise others on purchases, you can certainly get a feeling that BMW's are not on the approved list.
  • shiposhipo Member Posts: 9,148
    Personally I say form follows function; to that end I'd have no problem buying a new 3-Series of 5-Series, and immediatly swapping out the RFTs for a nice set of GFTs. Kind of a no-brainer.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I'd venture that not one in ten BMW buyers has a clue what RFTs are all about. And if they ARE aware that their car has RFTs, I'd venture not one in 50 could explain what they can, and cannot, do.

    (no, they are not solid rubber. No, they are not bullet-proof. Yes, you can destroy them by driving on them too long. Yes, they cost a lot more than the regular tire to replace. No, they don't last the life of the car).

    At least with "HD" TV (which we didn't clamor for either) we can SEE the difference----"oh, yeah, I get it".

    At best, RFTs are like ABS---people really don't know much about it, but it sounds good.
  • busirisbusiris Member Posts: 3,490
    In reference you your HDTV comment, I think i would have used the 3D-HDTV format as the example.

    Many who watch a lot of sports know exactly what HD format gave them, and sports over all else was one of the primary driving forces (especially in Europe) for the introduction of large flat screen HD TV. It really was, in large part, demand driven.

    On the other hand, the 3D feature seems to be much more manufacturer driven, rather than responding to a huge demand.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    edited July 2011
    Well we clamored for HD after we saw the difference (no-brainer) but I don't recall looking at my RFTs and saying "from now on, man, I want a piece of that for the rest of my life!" :P

    Yep, 3D is a perfect example of manufacturers wanting you to throw away your perfectly good TV set.

    Hey, can you guess what PERCENTAGE of *everything* we buy REMAINS in our possession after 6 months?

    1%
  • kyfdxkyfdx Moderator Posts: 235,175
    Hey, can you guess what PERCENTAGE of *everything* we buy REMAINS in our possession after 6 months?

    1%


    Since we spend most of our money eating out..... that's probably the case after just two days.... :surprise:

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  • busirisbusiris Member Posts: 3,490
    edited July 2011
    ... I don't recall looking at my RFTs and saying "from now on, man, I want a piece of that for the rest of my life!"

    Up until the introduction of RFT's, I don't think I know of a single case in which a car buyer made a decision to purchase or not based on the tires installed on a vehicle. On the other hand, I have seen folks walk away from a car because of color schemes, stereo set-up, interior options/fabric style, seat style, transmission-engine type/size, etc.

    Probably because, at the time, spares were standard equipment and the buyer most likely expected to replace the OEM-equipment tires at some point during ownership anyway. He would then get his/her own tire of choice...

    But, I do remember a time when space-saver spares were becoming the standard, and a lot of older folks were unhappy that they couldn't get a full-size spare. Of course, radials and rotational "dedication" went a long way towards discouraging regular tire rotation (the reason they wanted a full-size spare), which used to be the norm on bias-ply tires. Today, I suspect much less than 50% of car owners have their tires rotated (when its a possibility).

    BMW just pushed the envelope a bit further, with RFT's and the suggestion against rotating tires, which in models with staggered front/back sizes, is impossible. BTW, it's my belief that the reason my wife was able to get 50K miles on her MINI's OEM RFT's was because I rotated them regularly at oil change intervals.

    Still, I suspect one of the driving forces that led BMW to offer only RFT's (with a few exceptions) was the gradual reduction of sidewall height. A 30 or 35 series sidewall GFT doesn't allow for much margin in the case of a sudden blowout against wheel damage, but a rigid RFT sidewall does. That's just a guess on my part. But, even with RFT's. there are a high number of damaged wheels, so I can only imagine what it would be if RFT's weren't standard equipment.

    If I was the "decider", I would always allow the option of either RFT or GFT. It just seems the best solution, and with today's assembly line technology, it wouldn't create any additional headaches for production.

    However, no one asked me how I would do it...

    And, judging by BMW's sales, they seem to be handling the issue to, if nothing else... their own satisfaction.

    On the 1% retention number, I must be way out of the normal distribution range. Other than food and disposables (ie., toilet paper and the like), once I buy something, I usually keep it for years. My wife would gladly testify that I have 2 garages full of stuff I should have parted with 25 years ago...LOL!

    Then again, I'm not part of the "video-game" generation.
  • boston303boston303 Member Posts: 35
    Well, if someone informed you that the tires cost twice as much as other GF high performance tires and that they only last 30% of the life of GF tires I think that equates to a muiltiplier of 6 times more expensive than normal tires.. That wouldn't cause you a double take? I suggest few buyers had any clue of the poor performance and true expense of these tires. Shameful of BMW. Add to that BMW's insistence that you cannot replace the tires with normal go flats and again we have a car once heralded as the Ultimate Driving Machine being relegated to simply just another car with an tires that do not perform particularly well (I will except "M" series) and served up with an automatic transmission for drivers who would prefer to choose a car for it's color and not its performance elements. I know of many people who have purchased a car but had tires swapped out for another choice. Unfortunately that is not a true option with BMW. "Bimmer's" have gone to the "Beemer" crowd I fear...
  • shiposhipo Member Posts: 9,148
    "I know of many people who have purchased a car but had tires swapped out for another choice. Unfortunately that is not a true option with BMW."

    Why is it not a "true" option? Simply yank the RFTs and wrap on a set of GFTs the day you bring the car home. If the car is leased, store the RFTs until lease end and put them back on. If the car is purchased, peddle the RFTs on Craig's list and be done with them. :confuse:
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    This might be somewhat relevant...I was reading about the history of bicycles, which of course had a tremendous influence in America on the history of the automobile (bikers demanding better roads, bike manufacturers becoming car manufacturers, etc) and I read that when pneumatic bicycle tires came out, the switchover from hard rubber tires was almost immediate. In a couple of years, the rubber tire was dead, dead, dead.

    I'm sure not seeing this with RFTs. If there is an "improvement" over GFTs (debatable), then it is incremental at best.
  • shiposhipo Member Posts: 9,148
    "I'm sure not seeing this with RFTs. If there is an "improvement" over GFTs (debatable), then it is incremental at best."

    Let's see, in exchange for being able to drive (and potentially ruin) an RFT following a pressure loss event (both a positive and a negative), you get a tire which is heavier (a negative), rougher riding (a negative), louder (a negative), and with a shorter tread life (a negative). I'm not seeing the attraction. :)
  • busirisbusiris Member Posts: 3,490
    You should really get your facts straight. There is absolutely ZERO requirement from BMW that any owner stay with RFT's.

    I understand you dislike RFT's to the max, but you really don't seem to know much about them or BMW (can't repair RFT's, can't replace them with GFT's, etc).

    In fact, you seem to have a general dislike of BMW in general.

    Or, anyone who doesn't share your opinion of the company.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Well that's not *entirely* true, because if you leased a BMW with RFTs, I believe the leasing company would require that RFTs be on there when you return the car.

    To give you an idea of how desperate BMW/MINI owners are:

    image
  • capriracercapriracer Member Posts: 907
    If you want to convince BMW abot RunFlat Tires, you need to get in sync with their thoughts or they will ignore your input:

    RFT are more expensive. BMW would agree with that.

    RFT ride harsher. BMW would agree with that

    But BMW would not agree that RFT are noisier - in and of themselves - they can be made to be quiet just like GFT.

    And BMW would not agree that short treadlife is a property of RFT. They can be made to wear as well as GFT.
  • shiposhipo Member Posts: 9,148
    While BMW might well believe RFTs can be made to last as long as GFTs, the current crop of tires on the market suggests otherwise. How? The highest UTQG rating I can find for an RFT in a size which would fit a late model BMW is 400, that said, there are many GFTs in that same size which score 500 or better, 600 or better, and even a few which score 700 or better. Not exactly a ringing endorsement for the lifespan of RFTs. :P
  • capriracercapriracer Member Posts: 907
    But there are GFT tires with lower ratings than RFT, so what does that prove? You need to compare apples to apples. If you compare like tires, you'll find they have the same UTQG rating in both GFT and RFT:

    Examples: BS RE050A 140 A A, Michelin PS2 220 AA A, Pirelli PZero 220 AA A, Yoko Advan Sport 180 A A..... OK I'll stop now, but you get the idea.

    There is nothing inherent in a RFT that affects the wear qualities.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Well when I saw all four RFTs on my friends 2007 BMW 328ix melt before our eyes at 18,000 miles, I had to think something was up that was not mechanically related.
  • shiposhipo Member Posts: 9,148
    Hmmm, I'm thinking we're going to have to agree to disagree. My personal belief is that even though there are two tires called say "Michelin PS2", one in RFT form and one in GFT form, those two tires are essentially separate and distinct. True, they may have a similar or even identical tread pattern, but the carcasses of the two tires are completely different as are the driving characteristics.

    From my perspective, it is just as valid to compare tires from different manufacturers (or even different models from the same manufacturer) for tread life once you distinguish between RFT and GFT types.
  • busirisbusiris Member Posts: 3,490
    Well that's not *entirely* true, because if you leased a BMW with RFTs, I believe the leasing company would require that RFTs be on there when you return the car.

    Yes, a leased car usually must be returned in the condition in which it was leased, less reasonable wear-and-tear. However, nothing in any lease I have ever seen even suggests that RFT's can't be replaced with GFT's, just as long as the car is returned with like-original equipment tires on it.

    While I understand what you are saying here, it really doesn't apply to any BMW policy regarding the requirement of RFT's on its vehicles. The choice of GFT's or RFT's are entirely up to the owner/lease holder, and no warranty issues are tied to the use of non -OEM equipment tires, as long as the tires are reasonably sized for the car.

    Off hand, I know 4 BMW/MINI owners who have moved to GFT's with no reactions from BMW or MINI.

    After all, doesn't the M3 come with GFT's and a patch/plug/repair kit?
  • cdnpinheadcdnpinhead Member Posts: 5,498
    . . . no warranty issues are tied to the use of non -OEM equipment tires, as long as the tires are reasonably sized for the car.

    While what you say here is entirely accurate, there are numerous reports of BMW dealers telling people that replacing RFTs w/ GFTs will "void the warranty" and/or that it "can't be done."

    Balderdash for sure, but it does happen.
    '08 Acura TSX, '17 Subaru Forester
  • busirisbusiris Member Posts: 3,490
    Oh, I'm sure it happens...

    But then again, there are dealers across the spectrum of manufacturers that tell owners having a non-dealer entity service their car (or even perform an oil change) will void their warranty.
  • kyfdxkyfdx Moderator Posts: 235,175
    Leased BMWs that come with run-flats, have to be returned with run-flats...

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  • busirisbusiris Member Posts: 3,490
    edited July 2011
    Leased BMWs that come with run-flats, have to be returned with run-flats...

    I think everyone is in agreement with that statement.

    The specific question at hand was whether or not a lease-holder could swap the RFT's out for GFT's and run GFT's during the term of the lease, then return the car with the original RFT's re-installed (or a tire like the OEM RFT's). And the answer to that question is a definite "yes".

    As in any lease, the car is to be returned at lease-end in the delivered condition, minus accepted wear and tear.... unless wording in the lease specifies otherwise.

    There is no prohibition against running GFT's on any model BMW sold in the USA (at least, none that I am aware of...).
  • capriracercapriracer Member Posts: 907
    Shipo,

    You may have inadvertently gone somewhere where we have an agreement!

    The RFT's we are discussing have 2 common characteristics - aside from RunFlat capability: They are high performance tires and they are OE (Original Equipment) tires.

    High performance tires are noted for their grip and they do this by sacrificing treadwear - and this is a common complaint about HP tires.

    OE tires are designed to the vehicle manufacturer's specs and that usually puts an emphasis on rolling resistance, and that is done by sacrificing treadwear and/or traction - and clearly traction is not one of the options in a BMW! Treadwear is a common complaint about OE tires.

    So it should be expected that OE HP RFT's - like the ones we are talking about - should have some complaints about treadwear - simply because they are OE and HP.

    Further, we should expect tire manufacturers to do something different for their OE tires to get them to have better RR - and that was where you wound up - a separate and distinct tire for each OE application - and that would include the tires under discussion.

    Further, the "separate and distinct" part would apply to both GFT's and RFT's - which muddies the waters even further - making separating out what is causing what very difficult to get a grip of.

    We know that OE GFT tires sometimes have wear issues and we know that replacement market GFT's generally don't. We also know that OE RFT's sometimes have wear issues, but what we DON'T know about is replacement market RFT's (at least ones designed for good wear qualities!) So while we agree that the tires under discussion are separate and distinct, we disagree over what is causing the wear issue - and we are missing some information that would be very helpful in sorting this out. We need to approach this problem from a different angle - and I would suggest we look at how these two types of tires are designed.

    The one over-riding design feature in a RFT is that there is something in the sidewall that greatly stiffens it. This certainly has implications on ride qualities and cost, but there doesn't seem to be a connection to treadwear. Wear rate is pretty much determined by the tread compound. And since rolling resistance, traction, and treadwear are affected by the tread compound, this would account for the differences seen in GFT's. That principle shoudl apply top RFT's as well.

    There are a lot of things that would adversely affect treadwear, but there is no inherent characteristic of RFT's that precludes good wear.
  • busirisbusiris Member Posts: 3,490
    There are a lot of things that would adversely affect treadwear, but there is no inherent characteristic of RFT's that precludes good wear.

    Disclaimer: I am not an automotive tire engineer, so this is only an observation...

    A tire maintains traction (grip) by several factors, including tread rubber compound, tread design, and flexibility.

    Inherent in that flexibility characteristic is sidewall "mobility". For example, one would expect to see better traction (and, by default, the ability to go at a faster rate of speed in making a circle) in a car equipped with a modern GFT (say 185/75 R15 sized tire) than the same diameter wheel surface that only had 1/2 inch of rubber surrounding the outer surface of the wheel.

    Why? Because we live in an imperfect world, and there are no uniform surfaces, so the tire surface must continually modify its section that is currently meeting the road surface.

    So, it would seem to me that sidewall stiffness does indeed play some part in traction, and in that regard, the easiest way to enhance traction is to use a softer rubber compound, which in turn, usually translates into less tread life.

    Now, as to what that differential might be, I couldn't say.

    But, I suspect that is the reason some RFT owners can get virtually the same mileage out of a set of RFT's as GFT's, because they don't get anywhere near pushing those limits (my wife and her MINI fit in this category, and she easily got 50K out of her OEM RFT's)....whereas, other RFT owners are more "spirited" drivers, and often have a driving style that enters that realm of traction "testing".

    Just my opinion and observations.
  • shiposhipo Member Posts: 9,148
    edited July 2011
    I managed to get more than 50,000 miles out of the OEM All-Season GFTs with a 400 UTQG which came on my 328i (and I never took it easy on those tires). Granted this is going back to before the RFT issue ever reared its ugly head, but not all OEM tires suffer from limited tire wear.
  • busirisbusiris Member Posts: 3,490
    ...not all OEM tires suffer from limited tire wear.

    I agree, but it can appear to be model-specific.

    For example, I have a daughter that has a 2008 Nissan Altima which came equipped with Continental Conti Pro Contact tires. After almost 40K miles, there is excellent treadlife left.

    My other daughter owns a 2009 Nissan Versa with the same tires (different size) and the tires were almost bald at 35K miles.

    Both cars were purchased new, and neither daughter is an aggressive driver. The only significant difference that I can identify is that the Versa went on a cross-country trip and back whereas the Altima didn't.

    Beats me why the same tire had such different wear results on the 2 cars...
  • capriracercapriracer Member Posts: 907
    Tire wear is highly variable. You can get widely different results even from identical tires. It all depends on how the tire is used.

    Most tire wear occurs in the cornering mode - that is when the steering wheel is turned. Make a lot of turns compared to how many miles traveled forward, and the tires don't get good "mileage". On the other hand, driving pretty much in a straight line is almost free - the tires will wear extremely well.

    To complicate matters further, each vehicle manufacturer has its own requirements for the tires supplied to its assembly plants. And an even further complication: Vehicle manufacturers are not consistent within their own product lines.

    So taking the 2 Nissans mentioned: Even though the tires had the same name on the sidewall, they were very likely built to very different specs, and built quite differently - and the most common difference is tread compound, which can have an affect on tire wear.

    It's probably most accurate to consider EVERY OE tire to be its own unique entity in spite of what it may say on the sidewall.
  • busirisbusiris Member Posts: 3,490
    edited July 2011
    To complicate matters further, each vehicle manufacturer has its own requirements for the tires supplied to its assembly plants. And an even further complication: Vehicle manufacturers are not consistent within their own product lines.

    So taking the 2 Nissans mentioned: Even though the tires had the same name on the sidewall, they were very likely built to very different specs, and built quite differently - and the most common difference is tread compound, which can have an affect on tire wear.

    It's probably most accurate to consider EVERY OE tire to be its own unique entity in spite of what it may say on the sidewall.


    That may or may not be the case. I honestly don't know...

    While I can easily accept that OEM's have tires made to their particular specifications, it seems doubtful (at least, to me) that multiple tires with the very same label and size can have different qualities. If nothing else, that would appear to create a nightmare in quality control, sales, etc.

    Also, it seems pretty short-sighted for a tire manufacturer to build an inferior tire for an OEM and then attempt to sell a differently formulated tire under the same exact label, unless the tire is inferior to the OEM tire. After all, if the OEM tires on my new car suck I'm highly unlikely to purchase the same brand, and even less likely to buy the very same tire style (even if I elect to stay with the same brand tire). That seems like as good a formula for killing sales that I have ever heard of...

    What I would like to see is a link to some information that verifies what you are saying. You might be 100% correct.

    I just don't know...
  • busirisbusiris Member Posts: 3,490
    On an additional note, I would think that, if tiremakers did as you stated, there would be tons of class-action suits against tiremakers due to differences within identical tire "lines/sizes". How would a potential buyer know what he was actually buying?

    Certainly, I would think that this "practice" would have come to light in the Ford Explorer/Firestone debacle.

    We all know OEM's want the lowest price possible, which usually translates into a product of lesser quality. If there's a way to save a buck, car manufacturers are prone to take that option. Remember the Ford Pinto? If I remember correctly, the estimated savings per car after making the design change to the gas tank location was something like $10-12.

    For OEM's to have knowledge of lesser quality tires on new vehicles, while tires labeled exactly the same way and look identical, but of higher quality are being sold in the aftermarket arena just strikes me as business suicide...

    Anyway, that's my opinion...
  • capriracercapriracer Member Posts: 907
    Busiris,

    You bring up a number of good points - but unfortunately, what I have stated is true. First you have to realize that the percentage of complaints for even problem tires is still pretty low. We may be discussing what appears to be a HUGE issue with these RFT's, but in reality, only a small percentage of people are having these problems - which makes getting these things changed a challenge!

    At one point in time, the company I work for was very unsophisticated as to how they did their tire line-ups - and the result was very poor wearing tires mixed in with some pretty good wearing tires. The folks in planning are doing a much better of it now and employ quite a few different techniques - and I'll name a few:

    - Creating a special line that is strictly OE, that way only that line of tire would generate complaints. The other lines wouldn't be affected.

    - Only participating in tire programs which are not likely to generate compliants - in other words, avoid those programs that look like losers. The OEM's do NOT like this. They want every one of the tire suppliers to participate in ALL the programs, so they get the best possible product at the best possible price. It's a trcky game to play for the tire manufactirers end - and the way this is usually handled is by making the bid more expensive so the OEM will go elsewhere. Doesn't always work!

    So let me address a couple of other pionts you made:

    Class action lawsuit? Yes, there have been some. But generally these are about poor performing tires, not differences. But this is all about money and if enough money is made in the original transaction, then lawsuits become a minor annoyance.

    The Ford / Firestone thing? Yes, it did come out, but if there is a customer who is going to buy a millon tires a year, he gets to dictate the particulars about what he is buying.

    Lesser quality? That depends on how you see this. From the OEM's point of view, they are delivering a vehicle that gives better fuel economy, with only a minor sacrifice in treadwear and traction. The fact that the end consumer doesn't see it that way is just one of those things.

    Nightmare in quality control, sales, etc.? Not as bad as you would expect. Only a few tires (meaning size/model) are problem children. Sophisticated dealers figure out which ones they are, and don't sell that particular size, except to folks who have good experience with those (remembering that only a few percent of people actually have problems with even problem prone tires!)

    Need a link? Well, here's my website that explains in much more detail:

    http://www.barrystiretech.com/oetires.html

    But that's only me explaining how it works. It isn't proof. How's 'bout this?

    Go down to any GM dealer. Look at the tires on a variety of vehicles. You should find that every tire has a TPC spec number embedded on the sidewall. That TPC number means that THAT tire has been made to GM's specs Now go to Tire Rack and look up that line of tires and see if you don't find there are many tires in the line.

    - OR -

    Go down to your local tire dealer and ask for a databook from a particular tire manufacturer. If they have a list that shows their OEM fitments, compare that to the list in the front of the book.

    - OR -

    Call one of the tire manufacturers and ask if the tire they supply to the OEM's are designed to that vehicle manufacturer's specs. You have to be careful how you ask this question, because if you word this a little differently, you may be asking a different question - keeping in mind that that the OEM's have a non-disclosure agreement with the tire manufacturer and the tire manufacturer doesn't want to jeopardize its business relationship with a customer who buys millions of dollars worth of products.
  • busirisbusiris Member Posts: 3,490
    edited July 2011
    First of all, I appreciate your response, and the time you dedicated to it...

    I completely agree with your RFT assessment as well. Relatively few, but extremely vocal (read LOUD) complaints.

    But...

    Sorry.... I'm not willing to accept your claim, at least based upon the info you provided...

    This sounds a bit more like an old wives tale or urban legend thing, or there would be available links to the practice readily available on the internet.

    Please, if you are inclined to do so, don't imply that its some sort of "secret" thing going on between manufacturers and tiremakers. There are far too many individuals inviolved for anything of such magnitude to be kept secret.

    Again, I don't deny the possibility that tiremakers make special labels/models of tires and sell them as only OEM products, but I find it difficult to accept that 2 tires, same sized and identically named, made by the same tiremaker (1 for OEM fitment and the other for general public sales), have differences in construction (unless there are changes across the board in the construction of said tire, such as an improvement).

    If what you say is true, its one of the best kept secrets in the automotive industry.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I'm wondering though how limited the complaints are, or would be, once the awareness of the problem is better known.

    What I mean is, since my friends 2007 BMW 328ix had her RFTs melt in 20,000 miles, isn't it safe to assume that just about everybody with the same car going the same distance on the same tires in the same large metro area would suffer the same fate?

    Maybe some people only *expect* 20K on a set of tires so they don't complain?
  • busirisbusiris Member Posts: 3,490
    I'm wondering though how limited the complaints are, or would be, once the awareness of the problem is better known.

    What I mean is, since my friends 2007 BMW 328ix had her RFTs melt in 20,000 miles, isn't it safe to assume that just about everybody with the same car going the same distance on the same tires in the same large metro area would suffer the same fate?


    Excellent points.

    IMO, the RFT issue (at least, as it relates to BMW) is similar to the (lack of) oil dip-stick issue. Relatively few complaints, but those that do complain are extremely vocal about it.

    That, coupled with the fact the buyer has no option when making the purchase tends to add to the complaint issue "loudness" of those complaining. As you said earlier in regards to owners having no idea what kind of tires they have mounted (at least, until replacement time), how many drivers actually check their oil nowadays? Ask 100 people you meet at a local shopping mall, and I would wager less than 20% (and that's probably a high number) ever check their oil level on any kind of regular basis.

    On your last statement, in theory I agree. But, reality is a different story. Even though 2 drivers in identical cars travel the same route and distances, there can be a range from little to extensive in how differently they drive that route.

    As an example, MPG. Its not terribly hard to find forum threads with owners of the same make and model vehicle, but getting huge differences in MPG. Grandpa probably is going to get more mileage than lead-foot-Larry.

    But, getting back to RFT's for a minute. From the physics perspective, in general, a stiffer sidewall translates into less flexibility. RFT's such as those BMW uses have stiffer sidewalls. That means that, in order to maintain the same ability to adhere to the road surface, a change in the compound meeting the road surface is required....usually a softer compound, but there may be other options. That's the theory...

    The $64,000 question is whether or not the increased rigidity in the RFT is significant enough (and if so, by how much) to cause the manufacturer to resort to a softer (and thereby, less durable) compound in order to maintain the expected and desired road adherence...traction? Also, even if adherence isn't an issue, does the stiffer sidewall cause more wear on the tire's tread-surface?

    Its pretty clear that a normal GFT with an external diameter of 26" will corner (ie, have better traction) at speed than a 24" solid steel wheel surrounded by a 1" thickness of rubberized tread surface.

    Now, it may well be that RFT's don't approach any of the above limitations, but I suspect that they do, especially in environments that call for more sidewall flexing... like those who drive more aggressively.

    Personally, I don't think the RFT issue is a "red herring", but I do think that many (but not all) who complain would just as easily get reduced mileage out of a corresponding set of GHT's.
  • capriracercapriracer Member Posts: 907
    ".......but I find it difficult to accept that 2 tires, same sized and identically named, made by the same tiremaker (1 for OEM fitment and the other for general public sales), have differences in construction........"

    Perhaps I wasn't as clear as I could have been.

    No, you are right. What usually happens is that a particular size of a particular model is supplied to an OEM, but both the OEM tire and the tires supplied to the general market place are the same tire. Those tires supplied to the general market place are called "downstreams" - as in they are downstream of what gets sent to the assembly plants.

    But the point I was trying to make was that within a line of tires, different sizes would be supplied to different vehicle manufacturers - and because of the differences, you should really think of OE tires as being unique to themselves.

    OK, onto your other posting:

    ".......That means that, in order to maintain the same ability to adhere to the road surface, a change in the compound meeting the road surface is required....usually a softer compound, but there may be other options. That's the theory......"

    Sorry, but that doesn't work in actual practice. While the sidewall stiffnesses are different uninflated, it is surprising how small the difference is when the tires are inflated - not that there aren't differences, but that it is not as big as one might think. The net effect is that the same tread compounds are used.

    As I have said before, there is nothing inherent in RunFlat tires that generates rapid treadwear, nor does this preclude good treadwear. It's just that RunFlats are only appearing on a few vehicles and the demand for good wearing, but lower traction, tires hasn't prompted any tire manufacturer to produce such an animal.

    Further, many folks complain about tire wear on their new car or truck - and they sometimes post that on websites such as this one. Almost every vehicle generates some level of complaints about tire wear. The trick is trying to sort out what's "normal" and what's not.
  • shiposhipo Member Posts: 9,148
    edited July 2011
    As I have said before, there is nothing inherent in RunFlat tires that generates rapid treadwear, nor does this preclude good treadwear. It's just that RunFlats are only appearing on a few vehicles and the demand for good wearing, but lower traction, tires hasn't prompted any tire manufacturer to produce such an animal.

    I'm still having a problem digesting that comment. Looked at from a slightly different perspective, I'd argue that a tire like the Michelin Pilot Sport A/S will easily out perform (from a ride, handling and absolute grip perspective) any of the all-season RFTs that BMW has mounted on the 3-Series while at the same time lasting many-many more miles before replacement is necessary.

    With the above thought in mind, does the current technology for RFTs preclude manufacturing a run-flat version of the Pilot Sport A/S which would last as long as the GFT version?

    FWIW, I live and drive agressively in an area with very curvy and hilly roads, and the fewest number of miles I've ever been able to put on a set of Pilot Sport A/Ss is ~45,000 miles; a far cry from what BMW 3-Series owners typically get from their OEM All-Season RFTs.
  • busirisbusiris Member Posts: 3,490
    edited July 2011
    ...What usually happens is that a particular size of a particular model is supplied to an OEM, but both the OEM tire and the tires supplied to the general market place are the same tire. Those tires supplied to the general market place are called "downstreams" - as in they are downstream of what gets sent to the assembly plants.

    But the point I was trying to make was that within a line of tires, different sizes would be supplied to different vehicle manufacturers - and because of the differences, you should really think of OE tires as being unique to themselves.


    OK, we appear to be reading from the same page now. This makes sense to me.


    ".......That means that, in order to maintain the same ability to adhere to the road surface, a change in the compound meeting the road surface is required....usually a softer compound, but there may be other options. That's the theory......"

    Sorry, but that doesn't work in actual practice. While the sidewall stiffnesses are different uninflated, it is surprising how small the difference is when the tires are inflated - not that there aren't differences, but that it is not as big as one might think. The net effect is that the same tread compounds are used.

    As I have said before, there is nothing inherent in RunFlat tires that generates rapid treadwear, nor does this preclude good treadwear. It's just that RunFlats are only appearing on a few vehicles and the demand for good wearing, but lower traction, tires hasn't prompted any tire manufacturer to produce such an animal.

    Further, many folks complain about tire wear on their new car or truck - and they sometimes post that on websites such as this one. Almost every vehicle generates some level of complaints about tire wear. The trick is trying to sort out what's "normal" and what's not.


    Well, as I said at the beginning of the discussion, I’m certainly no automotive tire engineer. And, judging from your web-site (well done, BTW) you appear to understand far more of the specifics of the situation. And, I agree that RFT's overall have a limited exposure, usually on more "driver oriented" cars, which may have a tendency to skew the wear "data".

    In other words, if RFT's were the only style tire available on, say a Toyota Camry, would the complaint level be the same?

    I can't say...

    But, I do think that, if the RFT tiremakers would make an effort to educate the public on what you stated above (and provide the scientific data to corroborate the claims) it would put many of the issues of RFT wear in perspective.
  • capriracercapriracer Member Posts: 907
    "....I'd argue that a tire like the Michelin Pilot Sport A/S will easily out perform (from a ride, handling and absolute grip perspective) any of the all-season RFTs that BMW has mounted on the 3-Series while at the same time lasting many-many more miles before replacement is necessary....."

    But you left out a critical item: Fuel economy (rolling resistance). Add that to the mix, and you can't say that.

    ".....With the above thought in mind, does the current technology for RFTs preclude manufacturing a run-flat version of the Pilot Sport A/S which would last as long as the GFT version?....."

    No, there is nothing inherent that would preclude manufacturing a RunFlat version of a regular tire - and in fact Michelin offers a RunFlat version in the model you mentioned (Hint: ZP = Zero Pressure!) The question is: Is it the exact same tire or is it an OE version that suffers from the same sort of problems we have been discussing.

    (OK, I did a quick check and it is indeed an OE tire and it looks like it is only available in sizes to fit Corvettes.)
  • shiposhipo Member Posts: 9,148
    "But you left out a critical item: Fuel economy (rolling resistance). Add that to the mix, and you can't say that."

    My current car came with low rolling resistance tires and oddly enough, when I swapped them out for the Michelin Pilot Sport A/Ss, my fuel economy improved ever so slightly (per my fuel log it looks like maybe a quarter of a mile per gallon improvement on average).
  • capriracercapriracer Member Posts: 907
    edited July 2011
    ".......RFT's overall have a limited exposure, usually on more "driver oriented" cars, which may have a tendency to skew the wear "data"......"

    I know this is going to complicate the discussion, but low aspect ratios are required for RunFlat tires - and yes, that is why they show up mostly on performance oriented vehicles.

    "........But, I do think that, if the RFT tiremakers would make an effort to educate the public on what you stated above (and provide the scientific data to corroborate the claims) it would put many of the issues of RFT wear in perspective......"

    Honestly? The complaint level for RunFlat tires is interestingly pretty low. As I have been explaining before, the issues about irregular wear and noise are being driven by BMW's camber - and this existed long before and exists with other vehicles as well. This is seen by the tire manufacturers as a vehicle issue - and since their customer (the vehicle manufacturer) is the source of the problem, they don't make a big deal about. If they were to publish anything, it would be a lose/lose for them. Besides fixing the camber problem isn't going to happen! BMW is locked into that.

    Interestingly, there was a vehicle manufacturer - I can't remember which one! - that had a sticker on the window that warned that the tires may wear out in 12K miles (or whatever it was). It's been a number of years since this first appeared and it doesn't seem to have spread - and I'm not even sure it is still done today!
  • whittenbergerwhittenberger Member Posts: 1
    Hello:
    This is an excellent thread, so I was hoping to get some related advice... I've had a 2010 BMW 750Li for 14 months and have had 6 run flat tires go flat. This seems like a lot. I've driven an Arnage, Range Rover (with low profile tires) and an SL500 over the past 10 years with the same driving pattern, and I've only blown one tire over the entire 10 years.

    I'm sure I hit pot holes - I live in PA and drive extensively in northern NJ.

    I've noticed that all 6 tires have had blown-out side walls. Is this common for run flats? If so, what can I do to stop having this problem. I joke to my wife that it costs me $450 each time I leave my driveway!

    Thank you for your help!
    -Rob
  • capriracercapriracer Member Posts: 907
    There is nothing inherent about run flat tires that makes them more prone to damage from potholes. This might be more about low aspect ratios - so my only suggestion would be to go to higher aspect ratios.
  • busirisbusiris Member Posts: 3,490
    Well, over the entire range of auto production, I agree that the complaint level is insignificant. But, we are talking BMW here, and as it relates to BMW, the complaints about RFT's are anything but insignificant.

    And, I understand the unusual negative camber effect that BMW uses, and how it relates to uneven (usually inner-tread) tire wear. Yet there is no shortage of owners that would tell you in the strongest terms that they experience no such wear when the RFT' are replaced with GFT's.

    Go back a few posts and examine the post with the picture of the MINI with the spare mounted on the back of the car, and pay special attention to the rear tires, and you can see a perfect example of that effect.

    If I had to guess, BMW isn't going to formally address the RFT issue, especially as long as sales are on the upswing. Why would they? I wouldn't, either.

    Still, it seems to me that it's a bit shortsighted for tire makers to ignore the issue, unless they really aren't interested in the future of RFT sales. As more and more BMW cars are sold, the issue will only continue to grow. Once a reputation has been established ( regardless right or wrong) it will be all but impossible to change it.

    Remember Betamax? It was actually a better recording format, with better definition, but VHS took the market because a VHS tape could, at the time, hold 6 hours, whereas the Beta maxed out at 5 hours. Few users actually recorded 6 hours at the time, but Beta lost out because it was considered inferior to VHS.

    Get enough "bad press" on RFT's and the same experience can happen.

    Again, it seems shortsighted for tire makers to just ignore the issue and hope it will go away at some point.

    I have RFT's on 3 of my cars, and I see both sides of the issue. I'm not a high-mileage driver, so tire wear isn't my number one issue as it is with others.

    The issue indeed may disappear all by itself, but IMO the jury is still out. Time will tell...
  • kyfdxkyfdx Moderator Posts: 235,175
    Interestingly, there was a vehicle manufacturer - I can't remember which one! - that had a sticker on the window that warned that the tires may wear out in 12K miles (or whatever it was).

    Not positive, but that may have been the Honda S2000.. Pretty famous for wearing out the OE tires in less than 10K miles...

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  • capriracercapriracer Member Posts: 907
    busiris,

    First, I am not saying the "issue" is insignificant. I am saying it is at a low level - as most of these sorts of things are!

    But I am not sure when you say "issue", which of the many issues we discussed you are pointing to. If you are pointing to the wear issue - as I said before, tire wear is highly variable. Toe plays a HUGE role in the camber issue - it's a multiplier. So it shouldn't be a surprise to hear that folks experience good tire wear with one vehicle, and poor tire wear with another. Plus we have to consider that many folks ARE getting good wear out of run flat tires.

    But I am curious as to what you mean by this: "......Still, it seems to me that it's a bit shortsighted for tire makers to ignore the issue,....". If we are still talking about the wear issue, I guess you didn't understand the implication that it is the vehicle manufacturers that set the specs - and that means the wear issue is basically controlled by the vehicle manufacturer - that the tire makers are constrained to deliver what the vehicle manufacturer asks for - right, wrong, or indifferent.
  • capriracercapriracer Member Posts: 907
    It wasn't Honda. It was Lexus, or Infinity or some other higher end make.
  • busirisbusiris Member Posts: 3,490
    It appears that you are leaning towards defending tire makers in the RFT debacle, in which I would include all issues... Stiff ride, excessive noise, low mileage wear, etc.

    That's fine, of course, but people don't buy tires just to have tires, nor do they buy cars without tires.

    My opinion is that car makers AND tire makers are pretty much joined at the hip, as it relates to tire classification....ie., RFT technology and offerings.

    Again, Ford and Firestone each attempted to throw the other under the bus on the Explorer disaster, but the general public perceived both parties as being guilty to some degree.

    IMO, unless the RFT manufacturers don't get a bit more proactive, RFT offerings will eventually fade. Unless we see some sort of legislation banning GFT's (think incandescent lite bulbs here), there may come a time that even BMW hears the call.

    BMW denied for years that it has HPFP problems with it's N54 engines, but all it took for that to change was a little of the "right kind" of publicity. The company policy literally changed overnight. Once an issue is deemed to be more negative than positive, things change...

    An old marketing saying goes "give someone better service than he expects, and he will tell a few close friends, but give him poor service, or worse yet, insult him, and he will tell everyone he meets". Remember how popular Steve Jobs comment was regarding the iPhone 4 reception problems... " You're holding the phone wrong!)

    Yes, many dont complain about RFT issues, but again, IMO it's the foolish man who thinks few complaints means no problems
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