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Thread: Attention run-flat owners

  1. #1
    Administrator thegunguy's Avatar
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    Attention run-flat owners

    Today I replaced the OE RE040 run-flat tires with a set of S-03s. Upon removing the original tires from the car, we discovered that two of the four in the set (one front, one rear) had several large areas where chunks of the sidewall had almost fully separated from the inside of the tire! As you can imagine, this condition seriously undermines the performance and safety of the tire.

    I suspect the cause was under inflation prior to my ownership of the car. When I picked up the car from the original owner all the tires were in the mid to low teens. So, I put them back at 34psi before driving back to TX. However, I have no idea how long the car was driven in this condition. Since then I have checked the pressure every few weeks, and I have had very little variation that could not be explained by differences in outside air pressure and temperature.

    As most of you know, run-flat tires give little, if any, visual indication of under inflation. So, be diligent about checking your pressures. All tires suffer damage from running low, but with run-flats you may have little indication that you have a problem until it's too late.

    In my opinion, run-flats have their place, but they're not a zero maintenance solution. Furthermore, the added weight and stiff sidewalls detract from the ride of the Z8. Replacing them with a lighter standard tire will yield a much smoother ride while lessening the impact of potholes, etc. - potentially guarding against shock tower deformation. Oh, and handling is just a bit better to boot!
    thegunguy

  2. #2
    Team Z8 dwz8's Avatar
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    Frightening experience to detect this, I guess.

    I wonder whether the former owner completely ignored the tire pressure warning?
    Best regards, Dieter

    ....

  3. #3
    Z8Mania
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    Perhaps there was no warning- if the pressure came out of all four tires at about the same rate then the system would not detect any problem. As I understand it, it measures the differences between the pressures (rotating radii).

  4. #4
    Administrator thegunguy's Avatar
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    I understand the same

    It's a difference based system.
    thegunguy

  5. #5
    Sport Button On - DSC Off Dogsbreath's Avatar
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    NEW Tires

    Hey gunguy

    I am due for new tires. Do you like the SO3's ? And do you have any comparison to the Michelins ??

    I'm highly ticked about the fix issue too. So much for the M5 and the X5 we were ordering.

    Dave P

  6. #6
    Administrator thegunguy's Avatar
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    From the reviews, the MPS2s appear to be "better"...

    ...than the S-03s, but if you want to maintain the OE size on the OE wheels, you're out of luck getting the MPS2s (at least for now). Most opinions agree that the S-03s are the best tire offered in the OE sizes at the time of this writing.

    As far as my impression, I've put about 100 miles on the S-03s, and I love them. You will find the ride to smoother than the OE run-flats, and the car is noticeably "stickier" in turns and during hard acceleration. I've found the DSC less intrusive since installing the tires. Compared to the run-flats, I don't think you can make a bad choice...just do something!

    Unless something changes soon, they're going to loose my M5 order too. Like many here, I am the local "car guy" that many friends consult when it's time to buy a new car. After years of devout recommendation of our Bravarian friends, I'm changing my tune.
    thegunguy

  7. #7
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Tires

    Thanks Gunguy

    I found some Dunlop Sport Maxx's which I got a good deal on. I am partial to the manufacturer. I'll let you know how they perform.

    Dave P

  8. #8
    Administrator thegunguy's Avatar
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    Please do...

    ...there are many comments on the S-03s, but not much on the Dunlops. I'm sure your review would be appreciated.
    thegunguy

  9. #9
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Exclamation Run Flatters Attention Please

    This will echo gunguy's original post. Please, if you have run flats, heed his advice. I did and it saved me from what could have been a potential catastrophe.

    I replaced my run flats today with Dunlops. The inside casing of one of my rear tires had large chunks of disintegration. There was absolutely no warning that there was anything amiss with the tire.

    Either the tire was underinflated or run deflated on the run flat rim. It had clearly been repaired and re-inflated. I am off to Fast Pass in Utah and speeds there will be high. Had the tire disintegrated then it may have been very serious.

    Please, if you are not the original owner or have ever run your car with low tire pressure, take your car in and take the tires off the rims. I could not detect the repair from the outside of the tire. I know the fellow I bought my car from was not aware of this but the original owner must have been.

    Incidentally, the Dunlop Sport Maxx's are INCREDIBLE. Huge difference. Handling is so much better. Better ride comfort. Road noise slightly higher but it is negligible. I highly recommend these.

    Dave P

  10. #10
    Sport Button On - DSC Off mollyshark's Avatar
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    Interesting comment on the chunks. Gunguy noticed a huge piece of my tire missing the other day. Checked pressure and everything fine. It's just...missing. Going to replace the devils anyway. Anyone look into the new Bridgestone RE050A Pole Position? I'm getting warm furries from them and think I might head in that direction.

    The good news is I sent in the final check on the Z today. Told myself I'd pay it off in less than a year and did. Gotta get that car off the books so can do the 650! Life gets complicated.
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  11. #11
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Thumbs up Tires

    Follow up on Tires

    I have 2500 miles on the Dunlop Sport Maxx tires now including some hard driving at Miller Motor Sports Track, as well as several high speed runs (over 140 mph), highway, city and technical road sections.

    I cant recommend these enough. The car handles far better, is stable at high speed and ride quality has improved. I would say there may be a slight increase in road noise but it is really hardly noticeable.

    I recommend these highly.

    Dave P

  12. #12
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    Found the same problem on my four year old runflats.

    They were fine but when they were removed to to repaint my wheels, there were in pieces on the inside.

    I will be switching them as soon as the new ones wear it when introduced to my new LSD being installed next week.

  13. #13
    Administrator thegunguy's Avatar
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    Since Dave's and my reports, I have heard from several other owners with a similar sidewall separation experiences with RFTs. This appears to be shockingly common.
    thegunguy

  14. #14
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Run flats

    My run-flats had major damage on the interior. I am not the original owner of my car so I cannot say with certainty that my old run flats were ever run 'low', though there was evidence of repair. However, the previous owner cherished the car and I think it is unlikely. I have concern what might happen to these things 'at speed'.

    A blow out at 80 mph is not like one at 50. My last major tire failure occurred with a canyon wall on one side and a fast flowing river on the other. I have never taken tires for granted since.

    I encourage anyone with these tires to consider changing them to the non run-flat variety unless you are positive that the tires have never been run low on pressure.

    Alternatively, maybe the design of the tire allows for deterioration for other reasons ??

    Dave P

  15. #15
    Sport Button On - DSC Off mollyshark's Avatar
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    I know this is a moldy oldy thread, but interesting thing happened today. When I took the runflats off several months ago, didn't detect any chunks missing or anything unusual and stuck them in a little storage thing I have. Finally got around to selling em today (guy named Marc who runs an Elise out at the Motor Ranch). Get an email from him a couple hrs ago and he took them to put on his old M5 and they wouldn't hold air. Tire guy played with em a bit. Take a look at these pix. These tires had less than 8K miles on em and you KNOW I'm not rough on this car. What scared the hell out of me is I was driving on these until a few months ago. Damn. Have more pix but you get the idea.
       
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  16. #16
    Administrator thegunguy's Avatar
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    We can't warn people enough about the run-flats.

    I believe that run-flat technology has probably improved dramatically since these tires were selected as original equipment for the Z8, but it appears that the older technology is not aging well. If you still have them. REPLACE THEM ASAP.

    Molly's is just another case in many similar experiences.
    thegunguy

  17. #17
    Team Z8 RRZ8's Avatar
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    Molly, could it be that this happened during mounting/demounting the tires ? It does not look like aging or an external damage (?) I know that my 'tire-guy' hates runflats because of the (in his words) excessive force he has to use to get the tires on the wheel, or of again (because of the firm side of the tire)

  18. #18
    Sport Button On - DSC Off mollyshark's Avatar
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    RR, I doubt it. There's been waaay too many reports of the same thing and I can't believe all of them were caused by the tire guys. For some reason, the materials in these tires just don't age well.
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  19. #19

    I never thought tires 'aged'

    but my immersion into tracking has taught me much. For the track you don't even want last year's stock because it has dried out and go harder than a frest tire. They really are just like donuts, best fresh out the oven, and nasty when they get stale. This is only a random guess, but I'm maybe the sidewall compund of the RF's is much harder/dryer to start with, just reaches a point of being too dry much more quickly?
    Andrew Macpherson

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  20. #20
    Team Z8 RRZ8's Avatar
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    On Molly's pictures it looks as if the part where the reinforced sidewall innerside (green in the picture) tears loose from the rest of the tire. Like Andrew said; maybe another compound ? Could this be with such a 'sophisticated' tire ? Could it be that the tire was under/overinflated for a longer time ?

  21. #21
    Administrator thegunguy's Avatar
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    The green section is where I had several whole chunks missing (1"x2") in two tires (see my original post in this thread). I believe Dogsbreath had the same issue. Regardless of whether it's related to age, inflation, or road conditions, these tires appear to be too fragile. All Z8 owners with the OE RFTs should consider replacing them. If you want to keep with the ?security? of run-flat technology, check out the Bridgestone Potenza RE050A RFTs. They're a few generations newer than OE tire, including updated materials and tread design. Since we don't have any reports on this tire, it's difficult to comment on them, but I assume that they're better than the problematic OE Bridgestones.
    thegunguy

  22. #22
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Runflats

    Yup - as Gunguy notes, the green section is precisely where the chunks were missing from my tires too.

    Dave P

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    It is exactly where I had chunks missing as welll. I can

    attest that they were never underinflated as I meticulously keep my tires in check. I have replaced all four OE Run Flats with the newer runflat technology.

  24. #24
    Administrator thegunguy's Avatar
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    Z8Eldred,

    Can you give us a report on the new RFTs? Model?
    thegunguy

  25. #25

    RE050's

    Just my 5c.

    I researched the RE050 RFT just before I decided to go to 20 inch wheels. Talking with two separate people at Tire Rack, I heard that the expected ride and handling with the RE050 vs. RE040 were about the same. If I recall, the published ratings on Tire Rack were a little higher for the RE050's.

    Do we think that this is somehow an isolated situation with the Z8's or this particular size of RE040's? Shouldn't we invite Bridgestone to review this situation?

  26. #26

    Thats a great idea....

    Shouldn't we invite Bridgestone to review this situation?
    Anyone have any direct lines of contact to them?
    Andrew Macpherson

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    AH60642: Still has RE040

    Quote Originally Posted by thegunguy View Post
    Z8Eldred,

    Can you give us a report on the new RFTs? Model?
    I stayed with the RE040 RFT's for now. I had replaced the rears prior to finding the problems with the front. I was advised by the tire tech that 5 years was too long to have the fronts on the car and that the age of the tire played a part along with the newness of the technology in the disintegration issue.

    My tech specified that the change to the REO50's would not provide any major change and did not recommend mixing them with my RE040's in the rear.

    The plan is to have these on the car for about two years tops and then switch to the RE050's.

    I may be wrong but he (the tech) suspected that since we got the first batch of the RE040's on the Z8's, it is possible that some of them just weren't up to snuff and that age is a factor on all tires not just RFT's.

  28. #28
    Administrator thegunguy's Avatar
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    Quote Originally Posted by Z8Eldred View Post
    I may be wrong but he (the tech) suspected that since we got the first batch of the RE040's on the Z8's, it is possible that some of them just weren't up to snuff and that age is a factor on all tires not just RFT's.
    There's no doubt that we're guinea pigs for the then "revolutionary" RFT technology. However, I've heard a fair number of horror stories from a variety of other car models from subsequent generations.

    As Andrew is fond of saying, "where there's smoke, there's fire". However, I have no interest in taking the issue to Bridgestone. Perhaps it should be mentioned to BMW. Since the majority of Z8 owners allow their cars to sit in the garage, likely with unmonitored pressure, they might want to issue an advisory/warning on the danger of neglecting pressure, age, etc.
    thegunguy

  29. #29
    Sport Button On - DSC Off jpklecker's Avatar
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    OE Potenza's

    I've still got the original Bridgestone Potenza's on my 2002 Z8 (approx. 25,000 miles) and I was wondering if the RFT's with problems were only from earlier Z8's or if all model years are encountering similar problems. I have noticed the right rear tire's tread is wearing faster than the left rear. The left rear was replaced after only about 2,500 miles on it (due to a nail in the sidewall) and has considerably more tread left. I have noticed a slight "squishing" sound, after each complete rotation, from the left rear tire when backing into the garage. I have regularly monitored the tire pressures and usually run at 35psi, never letting it get below 30psi. Is this "squishing" sound due to possible deterioration of the interior that everyone is talking about?

  30. #30
    Sport Button On - DSC Off Dogsbreath's Avatar
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    I believe the problem is the deterioration inside the tire - large chunks coming off the carcass - in most cases. This was my problem. I would suggest that if you run at speed or with any 'verve' that you consider replacing the tires. The car handles a lot better on non run flats too ! My car is a 2001. I am not sure what gunguys or Mollyshark's car is but I understand they had similar issues.

    Dave P

  31. #31
    Administrator thegunguy's Avatar
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    Thus far we only have observed this on 2000 - 2002 cars - no 2003. However, I don't believe the 2003 tires are any different by design, just possibly new lots (maybe not even that if BMW bought in bulk). Even without evidence on a 2003, I would not take the risk of putting yourself, passenger, or car at risk of a potential tire failure at speed, especially since all of us that have had the problem had it on multiple tires. Even if you want to stick with RFT technology, there are much better models available now. Don't forget the OE RFT on the Z8 was one of the first RFTs offered, if not the first high performance model - it's OLD stuff!

    I've said it many times - if you have the old tires, replace them. The ONLY downside is the cost. Newer models will increase the safety and performance of the car, and lighter tires (non-RFT) should help to prevent any frame issues.
    thegunguy