Run-Flat Tyres: All You Need To Know

What are Run-Flat Tyres?

Run-flat tyre, as the name itself suggests, is a tyre meant to run even when flat (punctured). After the successful development of rubber tyres in the late 19th century, the invention of tyres without air (due to puncture) came in the 1930s. World’s first run-flat tyre was designed by Michelin for military use, which can even survive bullet injuries. Later, tyre biggies like Goodyear and Dunlop tried their hand at it in the 1950s and 1970s respectively.

Today most of the premium and luxury performance vehicles are endowed with the option of run-flat tyres besides regular tyres. These innovative tyres can travel up to 130-150 km and under a limited speed of 70-80 km/hr. The high-end car makers don’t want their privileged customer to remain stranded at the time of puncture. Hence, run-flat tyres are either made available as an option or come standard. The run-flat tyres are offered in three types – self-supporting, self-sealing and auxiliary supported.

Types & technology of Run-Flat Tyres:

• Self-supporting tyre:

The tyres come with rigid sidewalls compared to usual ones and have internal support that allows the punctured tyre to rest on it instead of the rim. This averts injury to the wheel rim.  On the downside, such run-flat tyres with a self-supporting system provide you with stiff ride quality alongside limit the absorption capability as seen on traditional tyres. They are the widely used run-flat tyres across the globe.

• Self-sealing tyre:

These set of tyres feature a lining inside them that instantly responds if any small prick is made by any sharp object like a nail, screw, etc. It performs typically how the tyre sealant works and prevents punctures from causing further damage to the tyre. Compared to the self-supporting run-flat, the self-sealing tyres are not as popular and are offered in limited rim sizes.

• Auxiliary supported tyre:

The toughest out of the three, auxiliary supported tyre is equipped on army/military, government, VIPs and armoured vehicles. These run-flats are bulletproof and possess kevlar reinforcement, which is highly resistant against punctures. Its robust additional support ring/insert linked to the wheel aids in carrying the vehicle weight during a loss of air pressure. The run-flat ring/insert is capable of carrying heavy loads safely at high speeds for long distances. Such run-flats are very heavy and offer meagre fuel economy and relatively difficult handling. As a result, only heavy/large vehicles are outfitted with these rubbers.

Advantages & need for Run-Flat Tyres:

There are many advantages of equipping your car with run-flat tyres. Firstly, if the tyre gets pricked you can still maintain the control of your car thanks to its rigid sidewalls that take all the load. Secondly, in the event of a puncture, you don’t have to remain stranded changing the tyre in the middle of your journey, especially at the highways, which is troublesome as well as unsafe. Another merit is the increase in the boot space due to absence of spare wheel. And lastly, you get improved fuel mileage as there won’t be any excess burden to carry in the form of the spare tyre.

So, if you frequently travel long distances (alone or with family) and want to ensure a hassle-free and safe drive every time, topped with fuel savings then the choice of run-flat is open for you.

Cars compatible with Run-Flat Tyres:

There are several passengers as well as high-end luxury cars that can be equipped with Run-Flat Tyres (RFT). In most of the high-performance cars listed below, the RFT comes as standard equipment, while in others it can be upgraded from regular radial tubeless to run-flat tyres. However, the high purchasing and maintenance cost is involved in these tyres, they are not available in mass segment cars. It fits in vehicles like Audi A3, Audi A4, Audi A6, Bentley Continental, BMW 5 Series, BMW 6 Series, BMW 7 Series, Fiat Linea, Mercedes Benz New C Class, Skoda New Laura, Volkswagen Jetta and many more.

Popular Run-Flat Tyre Brands & Patterns in India:

There are a handful of international tyre marquees that offer run-flat tyres (RFT) in their India bound portfolio and these include the premium likes of Bridgestone, Michelin, Continental, Goodyear, Pirelli, etc.

Can run-flat tyres be repaired?

This may sound a bit weird, but yes, on the downside, the run-flat tyres cannot be repaired instead replacement is the only alternative. This is for the reason that due to the reinforced sidewalls of run-flat tyres it is not easy to detect a puncture. For which it is necessary to have a tyre pressure monitoring system (TPMS) in your car only then one can get an alert about the puncture. In such cases, if your TPMS indicates about the pressure loss (in any of the tyre), you should follow the recommended speed limit and get the tyres swapped with new ones without delay.

In reality, the technology used in the run-flats doesn’t allow long-distance or high-speed travel after a puncture. Another important thing is that these tyres even after injury or puncture appear okay. However, to invite further damage to the wheel/rim, it is better to seek professional help from the nearest tyre service centre.