DennisBeaverApril 5, 2014   •  By Dennis Beaver

“About a year ago I purchased a new 3 Series BMW. Now, I love the car but only learned last week that it has what are called Run Flat Tires. Before buying the car I had never heard of Run Flat Tires,” Darrell’s email began.

“I picked up a nail sometime ago and only became aware of it when I glanced at the car’s Tire Pressure Monitoring System light and it didn’t look normal.  But I do not really know how long it was telling me that I had a problem with one of my tires,” he continued.

“I drove to a local tire store and was told that the tire could not be patched and had to be replaced even though the nail was not on the sidewall.  The car runs fine, handles normally, and I have the feeling that they are just trying to sell me a $400 tire I don’t need.

“I read your column in the Hanford Sentinel every week and trust your recommendation. Am I being scammed? Is it true that these tires can’t be patched or are they like any other tire and generally repairable?

Run Flats are truly amazing tires but controversial

As we would soon learn, unless you own a BMW, Mercedes or some Ford products, or have actually experienced these amazing tires, most people haven’t heard of them, have no idea why they are called run flats, their benefits—and drawbacks—or why certain auto manufacturers are using these controversial tires.

We would also learn that one tire maker is about to offer them as replacements for conventional tires, even on vehicles not originally designed to use run flats.

And so, for a “Run-Flats 101” we spoke with Chris Maka, Senior Account Manager in Detroit for Continental Tire Company, one of the world’s largest manufacturers of automotive Original Equipment tires.

“In our cars, we are riding on the compressed air in the tires which supports the vehicle. So, when we have a flat, and the tire collapses, we aren’t going anywhere until it is changed.

“Now suppose, you pick up a nail, lose air, just like your reader, but the tire doesn’t collapse and the rim is not damaged. The tire remains intact, supporting your car’s weight and enabling you to continue driving 50 miles at 55 mph.  And, even when you look at it, chances are that it will appear just fine. That’s the idea behind Run Flat Tires, part of what we call an Extended Mobility System,” he added.

“These tires have very sturdy, reinforced sidewalls which help to support a car even when the tire itself is deflated.  They are so effective that drivers may not even notice a thing wrong, which is how your reader described his experience.

“But they should only be used in conjunction with a fully functioning tire pressure monitoring system (TPMS) and it is critical for safety that attention is paid to warnings of low tire pressure which all vehicles using these tires must have. This was something your reader unfortunately failed to do.”

Should Run Flats be repaired?  How far can I drive?

“This situation is a good example of why we at Continental do not recommend repairing a run flat tire.  Darrell did not know when the tire had lost air or how long he had been driving on it that way. There is no good way to know how severe the puncture is or what kinds of damage has been done to the tire. The integrity of any run flat tire can degrade, making it much less safe, so replacement is always the safe way to go,” he stressed.

As 50 miles doesn’t seem like a long distance, we learned from Maka that the driving distance on a “flat” run flat can be extended to 125 miles by using their Conti Comfort Kit. This consists of a 12 volt air compressor plus leak sealant and is extremely easy to use, as we found out by actually trying one out and obtaining a thumbs-up from the manager of a well-known local tire shop.

It is available from TireRack.com for $79.

These are controversial tires

“Buy a car with run flats and here is what you don’t get,” the service manager of one car dealership told us on condition of not revealing his name.

* You don’t get a spare tire.

* You don’t get the space for a spare.

* You don’t get any tools to change a tire!

“The only reason for these tires is to reduce vehicle weight and a slight increase in mileage.  But if you want most BMW’s, Mercedes and a few Ford products, that’s what you’re stuck with.

“This makes you think twice about road trips, unfortunately.”


Dennis Beaver practices law in Bakersfield and enjoys hearing from his readers. Contact Dennis Beaver.



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