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BMW 3-Series Run Flat Tires

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Comments

  • shiposhipo Posts: 9,152
    Kyfdx beat me to it. :)
  • Hey... even this blind pig can find an acorn, occasionally..

    Moderator - Prices Paid, Lease Questions, SUVs

  • shiposhipo Posts: 9,152
    He-he! ;)

    FWIW, I'm hating on the word "blind" these days. Why? Because Mr. Murphy doesn't know when to quit. In this case, my wife (who was carrying the family's insurance through her company) got laid off last year, just after I was diagnosed with a cataract in my right eye. Unfortunately said cataract wasn't at all bad (I still had 20/20 vision in spite of the cataract and my age), and insurance wouldn't cover the surgery. Fast forward to this year and, per my ophthalmologist, I’ve been told "my eye has fallen off a cliff;" I'm now legally blind in that eye. Annoying. :(
  • So your repair costs weren't because of the DWS tires you put on -- your original post made it sound like it was DWS tires' fault. I was planning to get them also. What do you have as flat protection?
    In your case the tire protection would have made out.
  • busirisbusiris Posts: 3,445
    I am NOT saying there aren't problems, I am merely pointing out that many of the complaints aren't caused by the tire's ability to operate without inflation pressure. For example, rapid treadwear is the result of the tire being a high performance tire with a tread compound being selected for grip rather than wear. Also, irregular wear is caused by BMW's camber spec.

    Put another way, if BMW were to discontinue the use of RunFlat tires, the rapid wear and irregular wear complaints would not be solved.


    Absolutely correct!

    Tire wear is directly related to:

    1. Rubber compound used in construction (soft .vs. hard)
    2. Setup of the car's suspension.
    3. The driver's characteristics (spirited .vs. tame)
    4. Road and environment conditions (road quality, temperature, etc.).

    As an example, my wife got over 55K miles out of the run-flats on her 2005 MINI, with visible tread left. On a Dodge equipped with non-run-flat Goodyear GT's, I had bald tires at 35K miles. Back in the 1970's, I had a Ford Courier pickup with 6-ply tires, and when I traded it at 100K miles, it had the original tires on it.... with tread still present. Of course, even when the truck was new those tires had practically NO grip and would break loose on the Interstate in a rainstorm if I floored the gas pedal at 70mph...

    BMW sets its cars up with reverse camber, which is great for handling in curves, but horrible for tread wear. This can be seen by following a 328i and watching the rear tire angle as the driver acelerates rapidly... the car squats down, and the spacing between the tires increases at the point where the tire tread meets the pavement.

    Generally speaking, comparing run-flats with non-run-flats is like comparing apples to oranges, unless you are comparing like tire construction rubber compounds. A softer tire wears faster, but gives better street performance. The harder the compound, the longer the treadlife.... all other things being equal.

    The issue is, most run-flats are also high performance tires....ie, softer rubber compounds. When owners replace them with non-run flats, they are also replacing a tire with one that has a different rubber compound. If the tire wears longer, they feel its due to the tire type, and ignore tire construction.

    Regardless if one believes this or not, it is indeed factual.

    Now, that isn't to say that run-flats don't have their issues. They are great for urban driving, but if one lives in a rural area (say....Wyoming), run-flats may not be the best choice for you, simply due to replacement supply issues.

    At the end of the day, however, I foresee the day when all new cars will be equipped with run-flats. Its a fuel usage issue. Weight of a spare and # of cars on the road....Its another way for car companies to eliminate weight and conserve space....thereby increasing fleet fuel economy.

    Of course, by then, supply won't be an issue, as all sizes and brands will be generally available.
  • shiposhipo Posts: 9,152
    edited November 2010
    Your post confuses so many issues it is almost difficult to figure out where to begin.

    Fact: Prior to the RFT debacle, BMWs were capable of rolling on the same set of tires for a long-long time (and the vast majority of folks that have reverted to GFTs are getting great tire mileage on late model BMWs). My two (pre-RFT era) BMWs are just a few examples of this phenomena as well.

    You missed one metric: 5. Sidewall dynamics. The sidewall architecture of the Gen1 and Gen2 RFTs contribute to accelerated tire wear.

    Comparing how long a tiny Mini went on a set of (all-season?) RFTs to a Dodge with Goodyear GTs (tires that have never been known for longevity) is a bit disingenuous; don't 'cha think?

    Your comment about how most RFTs are performance tires is completely false. Fact: BMW sells far-FAR more cars shod with (supposedly long lasting) All-Season RFTs than they do with Summer Performance RFTs.

    To say the things you claim to be "Fact" are in fact, "False" is an understatement.

    At the end if the day I foresee RFTs going the way of the dodo bird; errr, that until pneumatic tires are gone from the market place entirely. Of course the non-pneumatic tires that are likely to replace virtually all automobile tires are themselves RFTs, but nothing like the crap foisted upon us in this day and age (see the Tweel: http://en.wikipedia.org/wiki/Tweel ).
  • busirisbusiris Posts: 3,445
    Sorry....

    I learned a long time ago to NEVER attempt a discussion with one who already has his mind made up, regardless of what the facts actually happen to be.
  • shiposhipo Posts: 9,152
    Apparently you're referring to yourself.
  • busirisbusiris Posts: 3,445
    edited November 2010
    You might find the link below somewhat enlightening....

    or, maybe not.

    http://blog.bavauto.com/bmw-e46/proper-tire-care-part-2-for-longer-tire-life-red- - uce-negative-camber

    From the link...

    Camber: This is the angle that the wheels/tires make when viewed from the front or rear of the car. If the wheel/tire is perfectly vertical it has zeros degrees of camber. If the top of the wheel/tire tilts outward, this is positive camber. If the top of the wheel/tire tilts inward (toward the center of the vehicle), this is negative camber. Too much negative camber causes the inside of the tire to wear much faster than the outside. This is especially true on BMWs and MINIs which come from the factory with comparatively high negative camber for better control at high speeds. In this case, economy had been compromised – you have to replace your expensive tires more often. This is especially true of BMWs and MINIs that have been lowered (Fig 4) and/or have plus-size wheels and tires.
  • shiposhipo Posts: 9,152
    Your point is? The fact is that BMWs have been getting good tire mileage for years now, the factory camber settings not withstanding, and the only significant change in how long tires last has been the change over to RFTs.

    FWIW, I won't argue that tires will last longer on cars without the rear camber settings that many manufacturers are using these days; just that the RFTs have greatly contributed to accelerated tire wear.
  • capriracercapriracer Somewhere in the USPosts: 785
    Don't make me stop this car......No, no! That's not right.

    There seem to be reports of RunFlat tires not doing well, and there seems to be reports of RunFlat tires doing fine.

    There also seems to be reports of regular tires not doing well, and there seems to be reports of regular tires doing fine.

    So there is a awful lot of contradiction in all of this. So how do we sort this out? Is there anyone in a position to see the bigger picture?
  • I haven't posted for a while, but still read the discussion.

    I know there are 'for and against' for all tires, but from personal experience where RFTs had severe and irregular wear, fitting non-runflat tires gave a completely normal wear pattern without changing camber, or geometry. I'm now on my second set of non-runflat tires, different high performance tire, again wearing evenly.

    RFT's do not wear as well with negative camber, the stiff sidewalls do not allow the tire to flex to any degree like non run-flats.

    The wear rate is very similar over in the UK, to tires we have been fitting for years, that is not a big concern for us, just the pre-mature wear that wastes tires. We've had soft compounds on BMW car tires for years before RFTs, but RFTs have to be soft, or the grip levels would be disasterous. It helps compensate for the tire not really getting a good footprint.

    Ride issues are our biggest complaint, the crashing over poor road surfaces, and compromised dynamics.

    HighlandPete
  • cdnpinheadcdnpinhead Forest Lakes, AZPosts: 3,206
    Thanks, Pete.

    Always good to hear from you.
  • smarty666smarty666 Posts: 1,503
    edited November 2010
    Hi everyone, I was glad to find this thread b/c I really like the new 3 and 5-Series and was considering cross-shopping them when my Acura lease is up next year. I don't have the time to run through all the posts in this thread so I was hoping someone could just answer a few of my questions if possible b/c the few posts I have read have me really questioning whether or not to even cross shop BMW.

    1) Is BMW the only luxury company that has RFTs on all their models? and if so, why and when did BMW switch from using GFT to RFT?

    2) Do BMW dealerships carry GFT in stock or on order so that you can maybe swap off the RFT's for GFT's before you take it off the dealer lot at time of sale?

    3) How long have people typically gotten out of their RFTs before having to replace them with GFT?

    4) Has anyone, been able to go to an independent tire shop or service center and get an adjustment made to have the new RFTs taken off and GFTs put on in their place without having to pay full price for the GFTs?

    5) How did you go about getting a donut spare tire since BMW doesn't even provide that anymore?
    Thanks in advance for your help and information!!! :)
  • busirisbusiris Posts: 3,445
    edited November 2010
    1- On all models, I believe so.

    2-Depends upon the individual dealership, but I suspect no dealer in the US would remove run-flats from a new vehicle.

    3-Depends on the driving characteristics of the owner as well as the model/options.. Some get only 5K miles....others get upwards of 40-50K.

    4-Unknown. I guess its possible...But, why would any shop do it? Still, I suggest you call around and ask shops/tire dealers in your area.

    5-Try places like Tirerack.com. Remember, BMW offers no spare tire well or space for a jack, spare, etc.
  • shiposhipo Posts: 9,152
    edited November 2010
    1) I believe I've heard of other manufacturers dipping their toes into the RFT market (Honda/Acura and Toyota to name two), however, I don't believe any other maker has embrased the RFT concept like BMW has.

    2) Nope; in fact some ill-informed BMW dealers actually have the cheek to suggest you'll void part of your warranty if you change. That of course is a lie, but some of the sales and service folks don't seem to know any better.

    3) The summer performance RFTs that some as part of the Sport Package are typically good for ten to fifteen thousand miles, some even more. That said, due to the asymetrical tire size, the tires cannot be rotated and they typically start getting really noisy between the eight to ten thousand mile mark. Cars without the Sport Package are typically shod with all-season tires with the same size at all four corners; these tires not only last longer, they can be rotated which can partially mitigate the noise. If you're leasing most folks recommend you replace the RFTs with GFTs well before you get to the 5mm minimum tread deapth (per BMW-FS). Doing this will allow you to put the RFTs back on immediately prior to turning the car back in (once again, per BMW-FS the car must be returned with RFTs).

    4) I've not heard of any independent shops effectively buying the RFTs off of a new car, but I'm not saying it's impossible either. In my case, I had the factory tires yanked after only 714 miles and sold them on Craig's list for well over half of the cost of the new tires.

    5) Contrary to the previous post, BMW does in fact offer a jack and spare tire kit as an aftermarket accessory; that said, many folks simply opt to buy a kit like this: http://www.tirerack.com/accessories/detail.jsp?ID=38

    Keep us posted.
  • busirisbusiris Posts: 3,445
    edited November 2010
    Contrary to the previous post, BMW does in fact offer a jack and spare tire kit as an aftermarket accessory; that said, many folks simply opt to buy a kit like this:

    I stated BMW offered no SPACE for a spare or jack...Not that they didn't offer them as accessories.

    5-Try places like Tirerack.com. Remember, BMW offers no spare tire well or space for a jack, spare, etc.
    Get your fact straight.
  • shiposhipo Posts: 9,152
    Sorry, my bad. One wrong fact, compared to your numerous incorrect factoids.
  • highlandpetehighlandpete Posts: 46
    edited November 2010
    The spare issue, seems to be a market related problem. So in one sense you are correct. We can order a space saver spare kit here in the UK, just the wheel and tire, or a complete kit with jack, etc. Couldn't to begin with, but I believe the pressure on BMW was quite high, due to all the negative feedback, and folks needing the security of a spare wheel.

    As to other brands using RFTs, here in the UK we can opt for RFTs on some Fords, on some VAG models there is the option for RFTs. Mercedes does have a sort of 'half way' tire option. Named an 'MO Extended', allows up to 30miles @ 50mph and then you definitely bin it.

    What is surprising many UK users, cars are coming in without any spare tire even on the GFT models, even the mobility kit (pump and goo) can be an option. :surprise:

    HighlandPete
  • shiposhipo Posts: 9,152
    We have a few models (of which the names escape me for the moment) here in the States that list space saver spares and mobility kits as options as well. That said, it's still pretty rare that manufacturers sell cars over here without a spare tire and a jack. :)
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