Run Flat Tire Problems

wkn

New Member
#1
undefinedI own a 645ci, that I bought new about a year and half ago. I currently have 22,000 miles on Bridgestone Potenza tires. Today I had a flat about 200 miles from the nearest BMW dealer and 5 hours later riding in the tow truck we arrived at the dealer. It will take almost a week to get my car back for a simple flat tire. I was never aware of the lack of spare for this car and the run flats did not work because after a few miles the tire just about came off the rim.

I might as well have blown my transmission for the same complications as a simple flat tire. Anyone else have a similar problem? I love my car and its handling etc. but this lack of a spare is a journey that has no conclusion as of yet, becasuse I am writing this from a motel that I am staying at while waiting for a tire....I will never purchase another vehicle without a spare regardless of the price because of the uncomfortable feeling that I will now have driving in remote locations which is why I bought this car to begin with....it is a great alternative to riding my Harley on windy roads with air conditioning and heat but fixing any tire should not be so complicated. It will cost road side assistance about $1300 dollars and me about $500 as well as a week delay in my travels for a new tire.
In conclusion $1800 to fix a flat

Is there any hope of BMW replacing the run flats with a spare on future models or are flats just not important enough to bother with the convience factor?
 
#2
I am truly sorry to learn of your experience. I am driving an `05 645ci that I purchased "certified" a little over a month ago. My car is also equipped with the run-flat Bridgestone Potenza tyres. This car is my third experience with run-flat tyres. My first and second experiences were with an `02 and an `04 Lexus SC430. Those run-flat tyres were Dunlops and they were terrible. I switched them out of both cars for "standard" Michelin Pilots and had spare tyre kits installed. I can say from those experiences that the Bridgestones are far better run-flat tyres (ride, handling, traction) than the Dunlops. I am wondering if your experience is due in any part to your location. It struck me when I purchased my 645ci that those 19'' Bridgestone run flats might be a rarer breed of tyre than most, but that replacing the tyre would not be too difficult in my case because I live in the D.C. metropolitan area where there are a great deal of higher-end cars and more than a dozen national tyre shops. Another consideration is the nature of this type of tyre. It is typical for low-profile, high performance tyres to not last or wear well beyond 20K miles.

Can you say why it will take a week for your tyre? To my knowledge, Federal Express and UPS deliver everywhere.
 

wkn

New Member
#3
My location and timing were my primary problems for this flat. First it happened 200 miles from the nearest BMW dealer and in about as remote a location as you would find in the west. The flat happened on a Saturday afternoon and it took about 2 hours waiting for the truck and another 5.5 hours driving to get to Boise Idaho. In our area you can not order a tire until monday and it takes a minimum of 3 or 4 days to deliver. I am scheduled to have my car completed by this Friday but have opted to change all my tires as I have 22,000 miles on them and they are down to the wear marks. I am changing to Toyo run flats that are also recommended by the BMW dealer for my model. I ran Toyo's on my Audi A8L and had good luck with the high preformance tire wear and ride and they were about $500 less for 4 tires which I will burn through in about a year.

I live in Idaho and use my car to travel paved windy roads with my wife as an alternative to taking my Harley. The steering and driving dynamic's are even more fun than my bike which I have logged just under 100,000 miles on in 15 years. This is my first experience with run flats and the tire failed to perform but I am unclear as to why it failed or what caused my flat yet. I rented a car and continued my road trip after I met with the BMW dealer yesterday.

If you live in a city I doubt that you would ever have this problem but if you take the car on long haul trips out west in remote area's ..... beware!
 
#4
I hear you! It sounds in your case like "timing" was everything. Nonetheless, it seems that you are enjoying your car and I hope that will continue. One question: since it would seem that your 654ci is your "daily driver", what are you achieving on gas mileage? I use my `05.5 A4 as my my to/from work transportation (I live in Maryland and work in Virginia) because I can average 29 mpg on the drive. The 645ci remains in the garage until the weekend. Also, I would be interested in learning how the Toyos work for you. They put new Bridgestones on my car when they certified it but, as with your case, they will eventually wear out. Good luck and thanks!
 

wkn

New Member
#5
My car averages about 20-22 MPG. I am at 6000 feet. I hardly use my brakes until necessary so I am always down shifting and for all the windy roads I am in second on sharp turns, third on 30MPH corners and 4th below 60. On open freeways I am in 6th and I have found better management of the gear selection saves fuel much more than I anticipated. On hills downshift to 5th and note the power difference. Again I am at a higher altitude which may account for the benefit of gear selection.

If the Toyo's are a problem I will let you know.
 
#6
Article about low aspect ratio tyres

I found this article to be very informative about so-called "low profile" tyres. The article is from the L.A. Times.

YOUR WHEELS
Slim tires too cool to be safe?
The low-profile look exudes sex appeal and is selling well, but it's also pricey and a bit fragile.
By Ralph Vartabedian, Times Staff Writer
August 23, 2006


More and more motorists seem to be driving around in cars sitting atop what look like rubber bands: low profile tires on giant alloy wheels.

Those "rubber bands" are actually high performance or touring tires, and they're wildly popular among consumers who like a muscular, sporty look.

ADVERTISEMENT
But like an injury-prone star athlete, the buff body disguises some weaknesses. If you don't think so, just ask Los Angeles County Superior Court Judge Lance Ito.

Ito wrote to me recently about his two Audi A6s, whose low aspect ratio tires have had nine flats in the last 40,000 miles. He has gone through three sets of tires in that time. "I will never again buy a car with these low-profile tires," Ito said. You can almost hear his gavel bang.

In fact, engineers and safety experts say low aspect ratio tires — which have shorter sidewalls — are more vulnerable to road hazards, such as potholes and other obstructions that can test a tire's ability to flex at high speed, than their standard counterparts.

Officials from Goodyear, Michelin and Bridgestone — the three largest tire makers — all acknowledged in interviews that their low aspect ratio tires are more likely to be damaged by impacts in normal driving.

"They are more susceptible to pothole damage," said Bill VandeWater, Bridgestone's consumer tire products manager, in Nashville. "They don't have as much give before the tread contacts the rim. There isn't as much deflection capability as a taller tire."

What can you do about it? Well, advice from manufacturers can be kind of silly. Take, for example, Volkswagen's suggestion. "Avoid driving on roads with potholes, deep gouges or ridges," it tells owners of cars equipped with these tires. In other words, keep the car in the garage.

Nonetheless, consumers like the look. At Michelin, 20% of the tires it sells are high performance, and that figure is growing by about 10% annually, while sales of the standard "mass market tires" for cars are shrinking, said Lynn Mann, director of public relations for the tire maker.

Although consumers like the low-profile tires, safety experts are dubious about their practicality.

"My observation, other than styling, is why have them?" asks Clarence Ditlow, executive director of the Center for Auto Safety in Washington, D.C. "My advice to consumers is don't buy them."

Perhaps. But many don't have a choice. Manufacturers are offering autos with wheel wells designed to fit only a low aspect ratio tire, especially luxury cars with a sporty image.

Purchasing tires has always been a mystery to many motorists. When you buy a tire, there are three keys to its size: tread width, rim size and aspect ratio.

For example, a 205-65-15 tire has a 205 millimeter tread width and fits on a 15-inch rim. The 65 is the aspect ratio, a measure of a tire's profile. It is measured by taking the diameter of the tire, subtracting the diameter of the rim and then dividing by the width. The actual ratio in this example is 0.65, but typically described as 65.

To put it simply, the lower the aspect ratio, the shorter the tire. At one time, most tires had ratios of about 70 and rim sizes of 13 to 15 inches. Then, aspect ratios began to drop and wheel rim sizes began to grow.

Now there are rim sizes up to 24 inches and aspect ratios down to 25.

"It almost does look like a rubber band around the wheel," VandeWater said.

What's the point of this madness, other than sexy appearance? Ultra high performance tires almost always have low aspect ratios. These tires have speed ratings up to 186 miles per hour, super soft rubber that grips the road and construction that gives positive steering.

"It is meant for those people who see the freeway exit sign that says 40 mph, and they get that gleam in their eye and think: I bet I can do it at 80 mph," VandeWater said.

On their highway to heaven, however, these drivers are finding they have to change tires every 20,000 miles. And the ultra high performance tires are like ice skates on cold road surfaces, plus they cost a fortune to replace.

To get the same cool look but greater durability, manufacturers offer what they call touring tires. They have the low aspect ratios, but harder rubber that lasts longer. They also have a little more forgiving ride that doesn't report every pebble on the roadway.

Unfortunately, all low aspect ratio tires, both ultra performance and touring, are vulnerable to road hazards. And they are more vulnerable to under-inflation, many experts say.

"The lower aspect ratio makes it more sensitive to low inflation," said Max Nonnamaker, a tire expert and former chief engineer for a tire maker. "When the tire is taller or higher, you can lose more air. Any drop in pressure is more critical, because there is a shorter sidewall and you generate more heat."

An under-inflated tire flexes more as it goes down the road, generating more heat in the sidewall, which eventually can cause internal damage. Thus, keeping an eye on inflation is critical. But Ito said he checked the pressure in his tires two or three times per week and still experienced problems.

Tire inflation is always a controversial subject. Every tire has embossed on its side a maximum inflation rating. That's different than the the car manufacturer's recommended inflation, which is always less.

Nonnamaker believes that tire manufacturers should be required to also list a minimum inflation rating, below which tire damage occurs. But no tire maker wants to list such a rating. They could certainly do so voluntarily.

VandeWater said he believes that damage can occur if inflation drops 5 pounds below the level recommended by the carmaker. Typically, recommended inflation is 32 pounds, so you would be causing damage at 27 pounds. It is a tiny margin that very few consumers appreciate.

In a future column, I'll examine how the promise of tire pressure monitoring systems, which would warn drivers of low air, have failed to deliver useful technology to consumers.

*


--------------------------------------------------------------------------------
Contact Ralph Vartabedian at ralph.vartabedian@latimes .com.
 
#7
wkn said:
My car averages about 20-22 MPG. I am at 6000 feet. I hardly use my brakes until necessary so I am always down shifting and for all the windy roads I am in second on sharp turns, third on 30MPH corners and 4th below 60. On open freeways I am in 6th and I have found better management of the gear selection saves fuel much more than I anticipated. On hills downshift to 5th and note the power difference. Again I am at a higher altitude which may account for the benefit of gear selection.

If the Toyo's are a problem I will let you know.
Thanks! I drive mine in much the same manner; however, a lot of it is city driving and, as you know, that eats your mileage.
 

wkn

New Member
#8
Thanks for the article...it was enlightening. I am a high-end car junkie but was not aware of the low aspect tire problems until recently.....I appreciate your input.
 
#9
Donal in the wild west of ireland

Oh god, just when I thought I covered all the angles of getting my dream car checked over, I hear of run flat tyre problems the day before I buy it!
Im trading an 05 318 cabriolet for an 04 645i cabriolet. I managed to strike a good deal, as theres only 11k miles on the clock, I had the bodywork checked by a specialist and its perfect, and the mechanics checked too. What I thought was odd was there was no space for a spare wheel, then correctly presumed the 18" rims were covered with bridgestone run flat tyres. I vaguely remember reading something about problems with them, then went in search of info on the net which led me here. I really want this car, but not if it is going to give me tyre problems. Any words of re-assurance would be appreciated???

Donal
 
#10
donal said:
Oh god, just when I thought I covered all the angles of getting my dream car checked over, I hear of run flat tyre problems the day before I buy it!
Im trading an 05 318 cabriolet for an 04 645i cabriolet. I managed to strike a good deal, as theres only 11k miles on the clock, I had the bodywork checked by a specialist and its perfect, and the mechanics checked too. What I thought was odd was there was no space for a spare wheel, then correctly presumed the 18" rims were covered with bridgestone run flat tyres. I vaguely remember reading something about problems with them, then went in search of info on the net which led me here. I really want this car, but not if it is going to give me tyre problems. Any words of re-assurance would be appreciated???

Donal
Donal,
I purchased my `05 CPO 645ci convertible on impulse (traded-in an `04 SC430 with 11.8K miles on the odo) and I haven't looked back since. Note that "WKN" had over 20K miles on his Bridgestone run flats when one of them failed. These tyres last for only about 20K miles. As someone who swore off run-flats after my first SC430 (an `02 equipped with Dunlops) I continue to be extremely impressed with the Bridgestones. You will love the way this car performs; get it!
 


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