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Run flat tires pros and cons

Run flat tires or zero pressure tires as it is alternatively referred to, appeared in the market in the mid 1980s. Being relatively new, it was slow to catch on as most users were unsure of the benefits of this new concept tires. After establishing that these tires are clearly safer in an emergency blow out situation, vehicle manufacturers took the lead to adopt these tires as standard fittings.. Today, about 10 to 12% of luxury/ performance vehicle manufacturers have adopted run flat tires(RFT) as original fittings to their range of vehicles.

Before we go into details of run flat tires pros and cons, let us try and understand how a run flat tire is constructed and how different it is from regular tires.

Technical details

In any pneumatic tire, compressed air in the tire and the side wall of the tire play a major role in supporting the weight of the vehicle during its operation. In the event of loss of the air due to a puncture, there is no more support from the column of air and the entire weight is borne by the side wall of the tire. With a standard tire, the driver is unable to continue to drive the vehicle as loss of directional control becomes evident. If the driver still continues driving the vehicle, there is every possibility that the tire may dislodge from the rim resulting in rim and tire damage.

In the case of a run flat tire, the side wall is specially reinforced with hard rubber compound that will continue to support the weight of the vehicle in the event of a blowout. Depending on tire manufacturer and vehicle manufacturer preference, there are basically two different systems employed in run flat tires.

Self supporting system

Self supporting system

  1. Self supporting system- a specially reinforced side wall construction that will not allow total collapse of the tire in the event of zero tire pressure. The vehicle weight can be supported and the vehicle can still be maneuvered safely to the nearest point for assistance.
  2. Support ring system-this method employs a highly durable material band that fits around the inside of
    Support ring system

    Support ring system

    the specially designed EH2(Extended Hump)tire rim which will support the weight of the vehicle in the event of a zero pressure condition. This also allows for safe maneuvering of the vehicle to the nearest point for assistance.

Now that we understand how the run flat condition is satisfied by using either the self supporting system or the support ring system, let us look at the pros and cons of using these tires as standard installation on our present day vehicles.

Pros

  1. In the event of a blow out during high speed running condition, the tire will not go totally flat and the vehicle can still be controlled as per normal without causing any undue panic to the driver and other road users. In terms of safety and reliability, this is truly a plus point.
  2. The vehicle can still be driven at a speed not exceeding 80kmh for a distance of at least 80km to seek for assistance.
  3. A vehicle with standard run flat tires do not require a spare wheel, a jack and tool kit. Space and weight is therefore saved.

Cons

  1. In the event of irreparable or end of life replacement, the cost of replacement is much higher compared to non-run flat tires.
  2. Must be used with Tire Pressure Monitoring System(TPMS). This is mandatory as loss of pressure is not easily noticeable without a pressure monitoring system during driving.
  3. Poor ride comfort or harsher ride condition due to stiff tire side wall.
  4. Not popular and not readily available with tire dealers. Have to order and wait.
  5. Reduced tread life also due to stiff side wall used to support vehicle weight in case of a puncture.
  6. Tire manufacturers do not recommend repairing a run flat tire that has punctured. Replacement is recommended for safety reasons due to uncertainty of internal condition of the tire.
  7. Specially designed rims are required for run flat tires and after market supply for such rims is very limited.

Summary

Judging from the facts that we have gathered so far, it is quite clear to us as to why run flat tires have not really caught on well especially in the replacement market.

Feedback from consumer forums and reports clearly show low customer satisfaction levels in the field of cost of replacement, ride comfort and lifespan of the tire.

Tire manufacturers are clearly aware of such low customer satisfaction levels and we hope to see an improvement in these areas in the coming years.

It is clear that customers who have good ratings for run flat tires are customers who have experienced the safety and reliability of these tires particularly in a sudden blow out situation during driving.

If you are in the market for a set of new tires, for regular or run flat tires, you can now make an informed decision with what you have acquired from `Run flat tires pros and cons.

Please feel free to leave a comment or question below and I will be happy to respond to it promptly.

 

 

 

Nair

4 Comments

  1. Nair, When I first purchased my BMW 2 years ago they offered me a free tire replacement warranty for about $2,000. I was like, “I haven’t had a flat in 10 years, why would I purchase this?”. Well, I have had to replace 3 tires since then at $300 apiece. Beyond the expense, it’s very inconvenient and I am concerned that the next blowout will be while driving home from a New York airport late one night and I’ll be stuck in some god awe full place waiting to be towed with no replacement tire available in the area. These run flats are extremely unforgiving. When it comes to pot holes, the sides blow out. I used to love driving my BMW but now I hold my breath commuting in the NY metro area.

    • Hello Eric,
      It is a pleasure hearing from you and thank you so much for sharing your experience on the use of run flat tires on your BMW.
      Run flat tires were meant to give peace of mind for the driver in case of a sudden tire blow out as the vehicle can still be controlled and driven up to 80km to the nearest tire outlet for assistance. As these tires are not readily available, the `order and wait` situation for run flat tires put off many vehicle owners.
      Your experience of the side wall blow out when hitting pot holes is very unusual. In fact, run flat tires are designed with stiffer and more durable side walls.
      Could there be some manufacturing defect on this particular brand of run flat tires?
      If your experience of the side wall blow out is with the original tires fitted on the BMW, perhaps your feedback would be valuable to them for remedial action and quality improvement. The competition is great these days and tire manufacturers go to great lengths to safeguard their name and reputation.
      As a proud BMW owner, your feedback would be taken seriously.

  2. In your opinion what company sells the best tires? I switch from winter to all season tires every spring and fall. This is a great review because I had never heard the term ‘run flat tires’ before I read this. Thanks for a great education on these tires. Really well don.

    • Hello Peter,

      Thanks for dropping by and commenting on the blog on run flat tires. I am happy that this is good information for you. We all learn something new everyday.

      My favorite and reliable brands of tires are Michelin, Dunlop, Bridgestone and Yokohama. I am basing this on factors such as durability, reliability and performance. They are makers of tires for a wide spectrum of vehicles from cars to commercial, winter to all season. Amazon carries stock of a wide range of brands and sizes catering for most requirements.

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