PDA

View Full Version : Tire problems with 19in RFTs?


stancv
01-03-2012, 07:01 PM
Hi all,

Just ordered a 535xi GT and am worried about the many problems F10 owners are experiencing with bubbles in their 19 inch run flats. Given that the F07 has somewhat larger diameter wheels for the sport package ( 245/45/19 vs the 245/40/19 for F10), I'm thinking maybe there is more cushion to protect tires from road hazards. I am considering the tire & wheel insurance ($1149/5 yrs), and am wondering what are your experiences, whether you had tire/wheel problems and whether the insurance is worth the cost for the peace of mind for the F07?

jadnashuanh
01-03-2012, 07:46 PM
As to the tires, talk to a Goodyear tire dealer...the tires themselves have a Goodyear road hazard warranty on them. Wheels, on the other hand are not warranteed by either BMW or Goodyear, but your comprehensive insurance does cover it.

stancv
01-04-2012, 08:24 AM
As to the tires, talk to a Goodyear tire dealer...the tires themselves have a Goodyear road hazard warranty on them. Wheels, on the other hand are not warranteed by either BMW or Goodyear, but your comprehensive insurance does cover it.

Actually it is my understanding that wheels, as well as tires are covered/replaced by BMW if you purchase the BMW tire and wheel protection insurance. http://www.bmwusa.com/Standard/Content/Owner/BMWUltimateProtection/TireandWheelProtection.aspx I am interested in actual user experience with the 19 in tires included in the Sport package for 535x GT (style 235) to decide if it's worth buying the insurance.

wchewbaka
01-04-2012, 10:20 AM
I have a 2012 non-xdrive 535 GT with Sport Package. My 235 wheels came with Pirelli P Zero tires which made me feel better than getting the Goodyears given what I have read about bubbles.

But I bought the BMW Tire and Wheel insurance anyway because the whole run flat tire concept scares me. I became concerned about the potential inability to repair a tire at all in case of puncture. My understanding is that BMW Assist will not send towing if you have a puncture because you can drive the car. Then, you cannot repair the tire because the repair agency cannot tell how far you drove the tire. Besides, if you are on a trip where are you going to find BMW specific run flats? Hence, a long drive to a dealership. The run flats start to sound like they are a very expensive disposable commodity. On top of that my staggered wheel setup includes 40 aspect ratio rears with smaller cushion with greater risk to wheels.

So for piece of mind I bought the insurance after it was sweetened with a discount.....

I figured the ratio of tire and wheel price vs. 5 years of coverage was worth the risk/reward.

stancv
01-04-2012, 10:50 AM
I have a 2012 non-xdrive 535 GT with Sport Package. My 235 wheels came with Pirelli P Zero tires which made me feel better than getting the Goodyears given what I have read about bubbles.

But I bought the BMW Tire and Wheel insurance anyway because the whole run flat tire concept scares me. I became concerned about the potential inability to repair a tire at all in case of puncture. My understanding is that BMW Assist will not send towing if you have a puncture because you can drive the car. Then, you cannot repair the tire because the repair agency cannot tell how far you drove the tire. Besides, if you are on a trip where are you going to find BMW specific run flats? Hence, a long drive to a dealership. The run flats start to sound like they are a very expensive disposable commodity. On top of that my staggered wheel setup includes 40 aspect ratio rears with smaller cushion with greater risk to wheels.

So for piece of mind I bought the insurance after it was sweetened with a discount.....

I figured the ratio of tire and wheel price vs. 5 years of coverage was worth the risk/reward.

Did you have a choice in selecting the tire model? My CA is just telling me they're going to be all season.

Are you carrying any pump with sealant to try to fix the tire in case of hazard? I was considering the ContiComfortKit http://www.tirerack.com/accessories/detail.jsp?ID=38& , to try to get the tire to a shop before it's ruined by riding it flat. The other option, the BMW Mobility kit http://www.shopbmwusa.com/ProductList.aspx?CategoryId=83 , states that it's not for use with run flats.

wchewbaka
01-04-2012, 11:05 AM
No choice no prior info on the brand of tires.

It may be a xdrive / non xdrive issue

My tires are performance - yours may be all season more befitting the goals of xdrive

I do not carry a mobility kit. I figured if I was going run flat, I was all in....

If I was going to go non run flat without a spare I would have considered the mobility kit.

jadnashuanh
01-04-2012, 06:05 PM
Most punctures leak slowly - there's always the exception. So, if you carried a pump, you could keep stopping to keep the tire topped up and have a chance of them repairing the tire verses replacing it. TireRack tested a new Bridgestone RFT that rides better than the previous versions, but you still have the issue about potentially driving with it actually at zero pressure. The key is to not ignore the TPM warning when it occurs.

wchewbaka
01-04-2012, 06:35 PM
totally agree

I don't carry a mobility kit, but I do carry a pump

the other thing I thought about carrying is a plug kit which would slow down a leak in an emergency

However, I don't know what effect using a plug would have on my BMW tire warranty.

It is not directly relevant, but in California tire shops will not repair a tire when a plug has been used.

jadnashuanh
01-04-2012, 08:12 PM
The tire service info that I've found says not to put a plug in a RFT. Now, I couldn't find a service bulletin for all manufacturers. Most say, if you drive on a RFT with zero pressure, do not attempt to patch. If you treat it like a normal tire and stop, it could be patched, if it's patchable. Now, trying to convince the service person may or may not be easy. Hopefully, I'll never know!

stancv
01-05-2012, 06:44 AM
The tire service info that I've found says not to put a plug in a RFT. Now, I couldn't find a service bulletin for all manufacturers. Most say, if you drive on a RFT with zero pressure, do not attempt to patch. If you treat it like a normal tire and stop, it could be patched, if it's patchable. Now, trying to convince the service person may or may not be easy. Hopefully, I'll never know!

That's what I was thinking as well, to get it to a tire shop without riding on it on the rim and destroying it, to get it patched somehow. It just doesn't seem right to just replace a ~$400 tire for one nail. And if you have to replace a 50% worn tire on an x-drive, you just might have to replace all 4, to keep the same diameter, and not to mess the differential. Somehow, a little thing like a flat just becomes very scary.

jadnashuanh
01-05-2012, 12:35 PM
Most (all?) all-wheel drive vehicles have a fairly stringent max deviation in tire diameter that is allowed before you must replace all of the tires to match...so, that's an issue regardless of whether it is a RFT or a normal one. It's just that the RFT tend to cost more. Depending on the type of differential(s), some are more critical than others.

stancv
01-05-2012, 12:49 PM
Most (all?) all-wheel drive vehicles have a fairly stringent max deviation in tire diameter that is allowed before you must replace all of the tires to match...so, that's an issue regardless of whether it is a RFT or a normal one. It's just that the RFT tend to cost more. Depending on the type of differential(s), some are more critical than others.

Good point, but with non RFT I could change it with the spare and get it fixed and still use the old 'right-diameter' tire.

Wow, I just got a reply from my CA and he and the Service Manager see things quite differently:
"I spoke with my service manager and he said that it is a non-issue now. It use to be an issue in the past. The only time that it may be of concern, is if you put a new tire on with a different pattern. The tire warranty will replace only the damaged tire and it would be your option at your expense to replace any other tires."

What I understand from that is that keeping the same tire diameter to avoid destroying the differential is a thing of the past (that was my original question to him). Everything I've been reading says it is very much still an issue, yet the dealer says changing only one tire in x-drive doesn't matter; anyhow the tire insurance will pay for only the damaged tire. I guess it would be my option whether I want to ruin the differential.:dunno:

Wardman
01-08-2012, 01:54 PM
Fixing punctures on RFT's - most do not do it b/c unless you know exactly when you punctured it, you cannot guarantee that you weren't riding around with a copromised tire for weeks, and the sidewall may have been compromised prior to the TPMS alerting you sine it was picking up the extra load.... Fact or fiction, I'm not sure, but it makes sense to me

My RFT's - they are sitting at the dealer to be put back on when the lease is up and I put Micehlin Primacy's Non-RFT's on the car. I carry the Continental mobility kit. IMO - ride is significantly improved. I don't cringe when hitting small bumps, or hear the road noise when on harder/concrete paved roads. Straight flat roads the GY LS2's were not bad and performed well, but everywhere else I thought they were harsh.

I also got AAA, and have BMW roadsize along with my local BMW dealer coverage.

Maybe in a few years the RFT's will get better, hope so, but until then I opted out of them. And maybe BMW will make it our choice to decide RTF or not in the future....

jadnashuanh
01-08-2012, 02:05 PM
The TPMS should alert you when the pressure has dropped, and way before it is actually runflat unless it is a catastrophic failure. In that case, you'd probably hear the explosive noise when it fails. But, to mitigate liabilities, most places will not fix a run-flat, regardless.

TireRack tested a third gen Bridgestone runflat that shows a lot of promise...almost indistinquishable from the similar designed normal tire. They made the sidewall somewhat more flexible by incorporating alternating bands of softer material especially designed to dissipate the heat from running flat, so it can flex more and still perform its job. This may be the harbringer of better things to come. I doubt BMW will go back to non runflats, but expect runflats to improve.

FWIW, my Michelin runflat snows (PA2), with their softer tread, ride a bit better than the Goodyears that came with it with only a minor penalty in handling. they are a little vague in straight ahead, but it is a very slight difference.

stancv
01-08-2012, 06:00 PM
Thanks for all the helpful advice all. My other question from the original post was whether you bought the tire & wheel insurance from BMW (my offer was ~$1150/5yrs). Is it worth it or would I be better off to just buy another set of non-runflats and get a Conti kit?

jadnashuanh
01-08-2012, 08:27 PM
If you ever need to use the Conti kit's tire sealant, be prepared to buy both a new TPM and a tire (plus the tire people will curse you!). Plus, if it is a catastrophic blowout, you'll be stranded (course, you might be if it was that bad on a RFT as well). It's a tough call, either way. I don't fault BMW from going to RFT. They're not the only one, at least on several models. But, I'm not sure the tires have caught up to people's expectations. As it stands, at least for me, they don't bother me enough to consider switching. I'd prefer to be able to keep going, and you have a good chance of doing that with the RFTs.

wchewbaka
01-08-2012, 10:50 PM
Thanks for all the helpful advice all. My other question from the original post was whether you bought the tire & wheel insurance from BMW (my offer was ~$1150/5yrs). Is it worth it or would I be better off to just buy another set of non-runflats and get a Conti kit?

I don't think you can alleviate the cost of wheel and tire insurance with using regular tires in lieu of run flats. Regular tires temporarily patched with a mobility kit may trigger a replacement tire just like a run flat in the event of a puncture. The tire choice is really driven more by performance and variety preferences much more than economics.

The efficacy of insurance is more driven by your own personal risk tolerance and environmental factors.

If you live in an area where the roads are silky smooth and the roads never freeze then your need of insurance is less. On the other hand if you live in Detroit, whose roads I experienced years ago when my son worked for Ford, you definitely risk your wheels, not just your tires.... His alloys experienced leakage from cracks all the potholes induced.

In that same vein, I have earthquake insurance because of where I live. Most people in the USA would never consider it...

Your call

crbnblk12smkn
02-04-2012, 08:37 PM
I have a 2010 535xi sportwagon I got from Europe. It came with runflats and was great.....until I got back in the states and drove on our jack-up interstates! I had my rear right tire get wobbly on me, so instead of buying all new runflats, I replaced them all with a good set of all-seasons (Goodyear) all I had to do was make sure to replace and reset the TPM.:thumbup:

stancv
02-05-2012, 08:42 AM
I have a 2010 535xi sportwagon I got from Europe. It came with runflats and was great.....until I got back in the states and drove on our jack-up interstates! I had my rear right tire get wobbly on me, so instead of buying all new runflats, I replaced them all with a good set of all-seasons (Goodyear) all I had to do was make sure to replace and reset the TPM.:thumbup:

I was wondering whether you know what is the tolerance in diameter if you change just one tire in an x-drive. My dealer told me 'that's a thing of the past' and that all you need to care about is to put the same model tire. :dunno: Everywhere I read that for awd you must stay within a few mm or 1/32s, but can't find the specific tolerance for x-drive.

crbnblk12smkn
02-05-2012, 03:34 PM
Good question, sorry I can't provide much help for an answer. I have owned two 5 series, a 530 xi 2001, and now this 535xi sportwagon 2010. I have NEVER had a flat in my life, and since I have roadside assistance, I don't worry about it too much. I would if I were you try not to deviate too much in tire size/tolerance in diameter. I have found that depending on where you are in the country, dealerships sell BMW's but don't know squat about them.

stancv
02-05-2012, 04:06 PM
You are right, here in the Dallas area, they don't seem to know much about x-drives. I guess for sedans not too many people get the option.
It however seems somewhat irresponsible to claim that you can put a new tire on for an AWD car in the event of a flat, when the others would be worn out more than 50%, as long as it's the same brand. Hope to be able to claim your record of no flats in 10 yrs, and all this to be just excessive worrying on my part.

crbnblk12smkn
02-05-2012, 04:48 PM
Stancv, I might add that when I did recieve my current 2010 wagon in Germany, I was able to put 500 miles on it with the stock run-flats. Great maintenance on the autobahns, led me to believe that I would have no problem in the states. I moved to Kansas, where 80% of the roads are atrocious, and even worse after a hard winter. This is where my wagon developed the whopped rear-right tire. The roads in the states definitley beat them up. Thank goodness for roadside assistance. I did research for a good high-performance all season Non run-flat tire on Tirerack for my car, and never looked back. Run-flats are just too expensive to pay for on rough roads across the country. I hope my luck continues. Good luck. I am sure there are smarter people at the dealerships in your location showing up all the time.

stancv
02-06-2012, 08:22 PM
Stancv, I might add that when I did recieve my current 2010 wagon in Germany, I was able to put 500 miles on it with the stock run-flats. Great maintenance on the autobahns, led me to believe that I would have no problem in the states. I moved to Kansas, where 80% of the roads are atrocious, and even worse after a hard winter. This is where my wagon developed the whopped rear-right tire. The roads in the states definitley beat them up. Thank goodness for roadside assistance. I did research for a good high-performance all season Non run-flat tire on Tirerack for my car, and never looked back. Run-flats are just too expensive to pay for on rough roads across the country. I hope my luck continues. Good luck. I am sure there are smarter people at the dealerships in your location showing up all the time.

I like your optimism, regarding service people working for BMW. I in no way want to belittle their expertise, however some speak without thoroughly researching the problem at hand, and give the others a bad rep. Rough roads, and the predisposition noted by some F10 owners for their RFTs to develop 'bubbles' (can't think of the right word right now), were the reason I originally inquired whether others went with tire insurance for 19 in RFTs in F07s.

quackbury
02-08-2012, 07:54 PM
My God, there's a lot of really, really bad information on this thread. Let me try to debunk some of it.

First, it is BMW which refuses to patch a RFT under any circumstances. If you look at the Road Hazard warranty that many tire manufacturers include with their RFT's (I'm familiar with the Goodyear and Dunlop warranties) they SPECIFICALLY state that the manufacturer will pay to repair a RFT. If you subscribe to the notion that the tire manufacturer probably knows their tires better than BMW does, if get a nail in your Goodyear or Dunlop RFT, take it to a local Goodyear or Dunlop dealer and have it patched at the manufacturer's expense.

Second, the tire manufacturer's Road Hazard warranty can be pretty darn useful. If your RFT is getting worn down and you pick up a nail, you have the choice of (a.) having it patched at a tire dealer, or (b.) having it replaced at your BMW dealer (since they refuse to patch under any circumstances). If you go the BMW dealer route, the most you will pay for a new tire (even without the BMW wheel and tire coverage) is a pro-rated charge. E.g. if it's a $400 tire with 50% treadlife, you only pay $200 for a brand new tire. No charge for mounting, balancing, disposal, or the TPMS rebuild kit. This can be a pretty good deal in the long run.

Third, your BMW dealer will point out that the tire manufacturer's road hazard warranty only covers the tire, so if you bend or break a rim, you are on your own. They argue you are better served by the BMW wheel and tire plan, which they will gladly sell you for a high price and a hefty profit. But how many rims have you ever broken over your lifetime? In 20-plus years I have lost precisely one rim, and even that was covered by my comprehensive insurance. So one may argue whether the "wheel" part of the BMW wheel and tire warranty is actually useful.

Fourth, if you use a "mobility kit", you have ruined not just the tire, but also the Tire Pressure Monitor. The tire manufacturers' road hazard warranties specifically EXCLUDE coverage for any tire where fix-a-flat was used. So that mobility kit which seemed like a great idea on paper will likely cost you $550 or more if you use it ($400-plus for the tire, $100-plus for the TPMS, plus mounting, balancing and disposal of the tire you trashed). So is the mobility kit useless? Not entirely. The kit comes with a can of goop, and a compressor. If you use just the compressor - not the goop - to get pressure in the tire so you can drive it to the nearest tire shop, you're okay.

Fifth, "run flat tires" are marketed as allowing you to drive a stipulated distance at a stipulated speed. Buried in the fine print is the fact that if you drive on the RFT for ANY distance, the tire becomes unrepairable. Even if the flat was caused by a nail that could have been repaired for $25 at your local tire shop (or for free if your tire came with a manufacturer's road hazard warranty), you cost yourself $400 or more by driving on the tire. So many of us feel that RFT's are an out-and-out scam. Yes they will get you out of a bad neighborhood, but it's a very expensive proposition. Even if you stick with RFT's, you may want to look into carrying a mounted spare, particularly if you travel in parts of the country where F07 tires may be hard to come by. (And if you decide to carry a spare, don't forget you also need to carry a scissors jack and lug wrench).

dunderhi
02-08-2012, 09:09 PM
Fix-a-Flat advertises its product as TPMS safe; it even says it on the can.

quackbury
02-08-2012, 10:12 PM
Fix-a-Flat advertises its product as TPMS safe; it even says it on the can.

Then it must be true. ;)

I don't have the CD ROM with the tire warranties handy, but I am 99.9% sure that Dunlop and Goodyear both void the warranty if Fix-a-Flat or its equivalent is used.

stancv
02-08-2012, 10:39 PM
RE : quackbury

While you brought up some good information in your post, you really came at us, previous posters to this thread, like a pissed-off professor dealing with a bunch of unruly, dumb kids talking nonsense in his class. We are responsible adults, who paid considerable amounts of money for a car that is facing a potential issue due to the RFTs and lack of a spare. Nobody claimed to be the expert on the topic, intending to post 'really, really bad' information here, but to discuss and discover what is the best option for the situation we are in due to the RFTs that you can't fix if you drive on flat.

The fact that the tires can be fixed by the manufacturer is great, BUT you must have a spare tire to even have that option - we were discussing alternatives, as not everybody wants to fill their trunk with a spare + jack. One option, expensive as you indeed mention is the kit (whether you use the goo or not is another issue - at least you have the pump).

As you mentioned from your experience, I have never had a cracked rim, but then again, the largest rim I previously had was a 17 vs the 19 on the GT. The less cushion there is the higher the risk of bad stuff happening. I am not happy by being seemingly coerced to buy the tire insurance, I would rather keep my money, but it seems like a prudent tradeoff in my case.

quackbury
02-09-2012, 06:00 AM
RE : quackbury

While you brought up some good information in your post, you really came at us, previous posters to this thread, like a pissed-off professor dealing with a bunch of unruly, dumb kids talking nonsense in his class. We are responsible adults, who paid considerable amounts of money for a car that is facing a potential issue due to the RFTs and lack of a spare. Nobody claimed to be the expert on the topic, intending to post 'really, really bad' information here, but to discuss and discover what is the best option for the situation we are in due to the RFTs that you can't fix if you drive on flat.

My bad. I thought the folks posting here were looking for advice from folks who actually had experience with BMW's and RFT's. I didn't realize it was a thread intended for folks with little to no experience to speculate about what life with RFT's would be like - sort of like kids in middle school talking about sex.

Knock yourself out.

/Subscribed

stancv
02-09-2012, 06:50 AM
My bad. I thought the folks posting here were looking for advice from folks who actually had experience with BMW's and RFT's. I didn't realize it was a thread intended for folks with little to no experience to speculate about what life with RFT's would be like - sort of like kids in middle school talking about sex.

Knock yourself out.

/Subscribed

Missed my point, but regardless, with the sarcastic, patronizing communication style you are unlikely to get your knowledge accepted by some, me included.

wchewbaka
02-09-2012, 09:56 AM
You know, stancv, I thought all we were doing was sharing perspectives, opinions, and experiences in helping you (and all of us) with your original question.
I think our conversation got to the point that there are options that different people choose that are right for them. All have trade-offs.
We may have meandered, but all the points were mentioned - just not presented as THE ANSWER
If there was only one answer we would all have Black Model Ts.

jadnashuanh
02-09-2012, 07:19 PM
Bottom line...heed the TPMS! If you're lucky, the leak isn't too bad and you have a pump so you can keep it inflated while getting to service. But, consider that there are places you can't legally stop to do this (some tunnels, bridges, causeways, parkways). Then, there are places you'd really rather not have to stop. In those situations, at least with a RFT, you can safely continue at moderate speeds. With a regular tire, you'd be crawling along at maybe 10mph and almost certainly ruin the wheel, where a RFT would preserve it, if it was intact in the first place.

If you can get to a repair place and still have reasonable air pressure, you should be able to patch it if it is in a patchable location. If you drove with it flat, you're pretty much out of luck and will need a new one. WHen I first looked into this, I was able to find a few manufactuers' guidelines, and those I did find, their policy was to recommend against patching a RFT, regardless. Don't remember the thread, but I posted some links to those pdf's.

stancv
02-11-2012, 12:28 PM
You know, stancv, I thought all we were doing was sharing perspectives, opinions, and experiences in helping you (and all of us) with your original question.
I think our conversation got to the point that there are options that different people choose that are right for them. All have trade-offs.
We may have meandered, but all the points were mentioned - just not presented as THE ANSWER
If there was only one answer we would all have Black Model Ts.

I agree, and the discussion has been most helpful indeed, at least to me, and would like to thank all for the advice provided. The one universal answer, that would suit everybody in all cases, I agree does not exist, as it is a case by case situation depending on your preference for risk.

stancv
02-11-2012, 12:29 PM
Bottom line...heed the TPMS! If you're lucky, the leak isn't too bad and you have a pump so you can keep it inflated while getting to service. But, consider that there are places you can't legally stop to do this (some tunnels, bridges, causeways, parkways). Then, there are places you'd really rather not have to stop. In those situations, at least with a RFT, you can safely continue at moderate speeds. With a regular tire, you'd be crawling along at maybe 10mph and almost certainly ruin the wheel, where a RFT would preserve it, if it was intact in the first place.

If you can get to a repair place and still have reasonable air pressure, you should be able to patch it if it is in a patchable location. If you drove with it flat, you're pretty much out of luck and will need a new one. WHen I first looked into this, I was able to find a few manufactuers' guidelines, and those I did find, their policy was to recommend against patching a RFT, regardless. Don't remember the thread, but I posted some links to those pdf's.

:thumbup:

Great summary.

magnumforc
02-15-2012, 04:01 PM
I've posted in other posts on this forum on my experience with the Goodyear Eagle LS2 RFT tires. Warranty makes more sense when you look at the overall convenience of not having to carry the spare tire, the weight od the spare, and the ability to drive a distance following a road hazard issue. Several points to make:

1. Goodyear respects the warranty fully and covered the last tire 100% during the first year of use with less tha 5K on the tire.
2. BMW Dealers often have no clue about how the warranty works so be ready to educate them about it or you'll end up paying full price for the tire and mounting, etc. Many would rather charge you than bother making the call to Goodyear customer service.
3. If you patch/plug an RFT and then have a subsequent failure of any kind, the manufacturer will then have grounds to deny the claim regardless of how much prorated treadwear, mileage or time is available under the warranty. In short, you'll likely void the warranty.
4. Following maintenance at BMW, always check your tires yourself for proper pressures, etc. Our 2010 GT came back last week with low pressire in all 4 tires following the changing of the brake fluid, with the left front so ow it triggered the TPI warning system. Carefully ispected the tire and it's fine, just was 8 PSI low on pressure! Go figure, since I checked the tires a week before and reset the TPI system with the temperature being about the same. Crappy mechanic! 2011 GT came back this week from oil change with air pressure never checked!

pal joey
02-18-2012, 04:42 AM
a couple of tire questions,i been thinking of,but dont have answers for.

has anyone here experimented with differant tire pressures,on the 19 inch ls2 ?
bmw recommends 35 front 39 rear.
variations in pressure will affect affect a number of things,but will it affect the probability of sidewall bubbles?
if so what pressure would it be better to run at?

also what about 535 gt with x drive and sport package.
i know their tires are sized differant then f10,and i believe they have staggered sizes .
but i think their fronts are 245 45 19. what make and model tire are o.e. on gt sport with x drive?
does the bubble problem also exist with gt drivers? and if it does is it on the same level or to a lesser degree?

would going from 245 40 19 to 245 45 19, have a minimal , significant, or no differance at all in regard to sidewall bubbles ?
since the 245 45 would require more air then the 245 40,it that a plus ?
does more air volume reduce the chances of bubbles?
if it does can adding a couple of more pounds then recommended pressure reduce the the chances of damage?
or would it have the opposite affect,making it more difficult for the tire to contract and expand on impact?

or is the amount of air volume in a tire a non factor and what is a factor is the increased height of the sidewall.

jadnashuanh
02-18-2012, 09:48 AM
The taller the tire's sidewall, the more cushion it has and the less stressful with the same impact (and, be less likely to damage a wheel). That's why the tires on the stock 18" wheels seem to be less prone to problems than opting for either the 19, 20 or even larger wheels. To keep the gearing the same and the odometer and speedometer accurate, the overall running diameter of each of the stock tire/wheel combinations is almost exactly the same. The stock 18" tires are 245/50-18. On the 19", it could be either the same F/R at 245/45/19, or that front and 275/40-19 rear. On the 20", it's 245/40-20 F and 275/35-20 R.

Rolling diameter can roughly be calculated by taking the width*aspect ratio/100 *2 + wheel diameter. For example, the 245*50/100*2 (in mm) = 245 = 9.65"+18" or a diameter of 27.65". The 20" 275/35-20 comes out to 275*35/100*2=7.58 +20" or a diameter of 27.58" (close) and the front at 7.71 +20 or 27.71" (closer to the stock 18" in diameter ?).

The tire sidwall height on the stock 18" tire is 245*50/100 or 122.5mm (4.82"). On the 20" 275/35, that drops down to 3.79"., or slightly more than an inch less (28% less).

Running higher pressure might prevent the tire from compressing enough to damage a wheel when you hit a bump, but it also would tend to put more stress on the sidewalls. too soft, and you could bend the sidewall and potentially break some fibers. From the user's manual, the taller the tire, the less pressure you need in it, with (depending on load and speed) the 18" tire calls for 32/35 and the 21" tire 38/44, both for speeds up to 100mph. So, the 21" tire, when you hit a bump, would be putting lots more stress on the sidewall from peak pressure than the 18". If the bump was severe enough to nearly hit the wheel, neither would likely survive, but keep in mind the 18" tire has more sidewall to compress than the larger wheels have.

To me, I prefer the better safety margin on the smaller wheels. If you want the (slight) potential performance increase (and who really uses it on the public roads), or the 'look', then you will end up paying for it both up front, and potentially over the life of the vehicle in damage replacement costs, and just normal replacement costs - the lower profile tires tend to be a lot more expensive than the taller ones in smaller diameter. AutoWeek issue that just came out had their long-term 5-series test results in, and the biggest issue was with the tires/wheels - they spent a lot of money on replacements. If you live where there are freeze/thaw cycles, and spring potholes are a fact of life, bigger wheels, lower-profile tires will be an expensive option! the road maintenance across the country isn't what it used to be, and will probably never approach what is common in Germany where many of the roads were designed as emergency runways - their standard road is much sturdier than ours and less prone to potholes.

I don't think RFT will go away, and as BMW warns in their manual, larger wheels are more prone to damage (and I think that also applies to the tires). I also think that as more and more RFT are made, improvements in ride, durability, and longevity will be available. Bridgestone's third generation RFT tested out by TireRack with about the same comfort and performance levels as the equivalent normal tire, and much better than their second gen RFT. As of now, the sizes are limited, and they don't make one for many of the BMW models, but (hopefully) by the time I need new tires, they or others may have implemented some further enhancements to what is currently available. I also think that when you stretch the technology and go with bigger and bigger wheels, regardless of the type of tire, you're going to see more problems than with the 'stock' sizes.

So far, knock on wood?!, mine are all healthy, and wearing fairly evenly. Time will tell.

magnumforc
02-18-2012, 09:52 AM
The 2011 535i GT with xDrive and sport package did not come with staggered wheel sizes. It came with all-weather tires, Goodyear Eagle LS2 RFT's in 245-45/19. Have not had a bubble problem with these tires although I have had a tread/sidewall puncture covered 100% by warranty. Pressures I run are 35 front and 39 rear; vehicle sticker calls for 35 front and 38 rear.

Spouses vehicle uses the stock 18" Goodyear Eagle LS2 RFT's and she has not had the bubble issue either. I have to confess she has less than 2000 miles on her GT after 14 months of ownership! Not a high mileage driver. She turned in her 2008 328i with 4000 miles on the clock!

A harder tire reduces the fexability when hitting potholes or other impacts. Sidewall rigidity is a big reason for lack of flexibility and the main reason these are RFT capable. Increased air pressure will make them even more rigid, but in doing so will convex the tread, wear it out sooner in the middle, increase tire temperature and increase the potential for blowout from non-RFT issues. One or two pounds is not an issue as many do that for long distance travel. But the manufacturer knows what's beat for the tire in the long run as far as pressures go.

And, from what I know, air pressure doesn't increase the potential for bubbles. Failure of the tire substrate as a result of impact is the culprit at any pressure. Not that high pressure wouldn't add to the woes!

stancv
04-21-2012, 02:17 PM
I wanted to give an update regarding the tire/insurance issues discussed in this thread. I ended up declining BMW's tire& wheel insurance, as they were increasing the price on me (from $1150/5yrs to $1350/5yrs) between car order and delivery time. I instead purchased road hazard insurance from Discount tire for all 4 Good Year original tires (245x45x19) for $225. This way, I figure that for less than the cost of 1 tire I can actually drive on the RFTs on flat if I get one, and just get them replaced, without having to worry that I'll void their manufacturer's warranty.

Getting that insurance at a decent price gives me the peace of mind of knowing that if a flat does happen on the highway, I can just keep going, and I'll just get a new tire.

magnumforc
04-21-2012, 04:28 PM
a couple of tire questions,i been thinking of,but dont have answers for.

has anyone here experimented with differant tire pressures,on the 19 inch ls2 ?
bmw recommends 35 front 39 rear.
variations in pressure will affect affect a number of things,but will it affect the probability of sidewall bubbles?
if so what pressure would it be better to run at?

also what about 535 gt with x drive and sport package.
i know their tires are sized differant then f10,and i believe they have staggered sizes .
but i think their fronts are 245 45 19. what make and model tire are o.e. on gt sport with x drive?
does the bubble problem also exist with gt drivers? and if it does is it on the same level or to a lesser degree?

would going from 245 40 19 to 245 45 19, have a minimal , significant, or no differance at all in regard to sidewall bubbles ?
since the 245 45 would require more air then the 245 40,it that a plus ?
does more air volume reduce the chances of bubbles?
if it does can adding a couple of more pounds then recommended pressure reduce the the chances of damage?
or would it have the opposite affect,making it more difficult for the tire to contract and expand on impact?

or is the amount of air volume in a tire a non factor and what is a factor is the increased height of the sidewall.

535i xDrive with the sport package does NOT have staggered sizes. They come with all season RFT's of the same size front and rear, Goodyear LS2's on my 2011. Never had a bubble issue. Had a flat and Goodyear covered it 100% during the first year.

magnumforc
04-21-2012, 04:31 PM
I wanted to give an update regarding the tire/insurance issues discussed in this thread. I ended up declining BMW's tire& wheel insurance, as they were increasing the price on me (from $1150/5yrs to $1350/5yrs) between car order and delivery time. I instead purchased road hazard insurance from Discount tire for all 4 Good Year original tires (245x45x19) for $225. This way, I figure that for less than the cost of 1 tire I can actually drive on the RFTs on flat if I get one, and just get them replaced, without having to worry that I'll void their manufacturer's warranty.

Getting that insurance at a decent price gives me the peace of mind of knowing that if a flat does happen on the highway, I can just keep going, and I'll just get a new tire.

Good move. Just remember that Goodyear will replace the tires free during the first year or 2/32" of tread wear regardless of what the road hazard was and will pro-rate the tire up to 6 years. That at no charge to you. I don't remember if there is any pro-rating to the Discount guarantee; If not and all you just pay for is mounting and balance is a good deal indeed!

stancv
04-21-2012, 04:56 PM
Good move. Just remember that Goodyear will replace the tires free during the first year or 2/32" of tread wear regardless of what the road hazard was and will pro-rate the tire up to 6 years. That at no charge to you. I don't remember if there is any pro-rating to the Discount guarantee; If not and all you just pay for is mounting and balance is a good deal indeed!

It is my understanding that if you drive on the tire flat they will not replace it. In other words you must keep air in it in order to maintain that warranty (stop and pump, until you get to Good year). Am I wrong?
:dunno:

I also got the Discount Tire lifetime rotation and balancing for $65. The reason I went with them is that after I hit a curve last week with my other BMW, and it developed a bubble, they replaced it without comments with a new tire (MSRP~$225) and all I paid was $35 for insurance for the new tire. So with the GT, in case I get a road hazard I expect to pay ~$50 to insure the new tire. However, I'll definitely consider getting a free one from Good Year if I can. Do you pay balancing and installation there?

magnumforc
04-21-2012, 05:29 PM
It is my understanding that if you drive on the tire flat they will not replace it. In other words you must keep air in it in order to maintain that warranty (stop and pump, until you get to Good year). Am I wrong?
:dunno:

I also got the Discount Tire lifetime rotation and balancing for $65. The reason I went with them is that after I hit a curve last week with my other BMW, and it developed a bubble, they replaced it without comments with a new tire (MSRP~$225) and all I paid was $35 for insurance for the new tire. So with the GT, in case I get a road hazard I expect to pay ~$50 to insure the new tire. However, I'll definitely consider getting a free one from Good Year if I can. Do you pay balancing and installation there?

The replacement policy has nothing to do with Goodyear stores or dealers. It's Goodyear themselves who make the policy. If you puncture or otherwise damege an RFT during the first 12 months or 2/32 of use it gets replaced. No cost. Some places may charge for balancing and mounting, my BMW dealer did not once he spoke with Goodyear.

And yes, it comes from experience. I ran over a 4" spike and ran it through the tread right at the edge of the sidewall and drove the vehicle to the dealer. Only issue is that most dealers and that includes Discount do not have the tires available the same day. So, your car will sit until they get the tire from a distribution center. Remember the tires are made in Germany and not stocked by most dealers and stores. The good thing for me is that BMW gives loaners so I had wheels until mine was available.

Cheers.

stancv
04-21-2012, 05:40 PM
The replacement policy has nothing to do with Goodyear stores or dealers. It's Goodyear themselves who make the policy. If you puncture or otherwise damege an RFT during the first 12 months or 2/32 of use it gets replaced. No cost. Some places may charge for balancing and mounting, my BMW dealer did not once he spoke with Goodyear.

And yes, it comes from experience. I ran over a 4" spike and ran it through the tread right at the edge of the sidewall and drove the vehicle to the dealer. Only issue is that most dealers and that includes Discount do not have the tires available the same day. So, your car will sit until they get the tire from a distribution center. Remember the tires are made in Germany and not stocked by most dealers and stores. The good thing for me is that BMW gives loaners so I had wheels until mine was available.

Cheers.

Well, then for the first year the obvious choice is to get a new tire from Good Year by getting it serviced at BMW (and getting a loaner from them), and after that to use Discount tire and hope they get it fast. Thanks for the info. :thumbup:

stancv
11-30-2012, 07:05 PM
I thought I'd give an update on the tires; no problems so far at 13K miles. I do rotate them (front to back, same side) given that all 4 are the same size (x-drive), even though BMW suggests that you shouldn't . On another BMW I had bad thread wear on the rears so now I proactively rotate, against their advice (no uneven wear so far).