The principal benefit of Pirelli’s run flat technology – introduced to select Pirelli road tyres in 2001 using the lessons learned from rallying – is to allow drivers to continue driving for a while after most punctures, rather than being stranded by the side of the road. Rallying is where this technology was tried and tested for the first time, with tyres featuring a reinforced structure designed to allow driving after a puncture, which would otherwise cost several minutes in the heat of intense competition on a wide variety of roads.
NEW MATERIALS AND PROCESSES TO INCREASE COMFORT AND SUSTAINABILITY
Non-stop research and development into new materials and processes has helped Pirelli to improve driving comfort in recent years for cars equipped with Run Flat tyres. Thanks to new technology in the tyre’s structure, as well as advances in the materials used, increased comfort for drivers and better rolling resistance, with reduced fuel consumption and fewer emissions, are possible. These tyres are built to absorb bumps in the road and they offer similar levels of comfort as standard tyres, but with the key advantage of being designed to allow continued driving up to 50 miles at 50 miles per hour (mph) to seek assistance after most puncture events – even with reduced air pressure. The particular suspension characteristics of vehicles equipped with Run Flat tyres as original equipment should encourage the driver to always use tyres with this technology, including as replacement tyres when needed, to maximize the performance of the car.
USEFUL TECHNOLOGY FOR ELECTRIC VEHICLES, WITH AN EYE TOWARDS THE FUTURE
Spare tyres are not usually available in electric cars, in order to free up more space for batteries. That’s why several vehicle manufacturers choose extended mobility solutions such as Run Flat or Seal Inside to minimize inconvenience and allow the driver to get to a shop in the event of most punctures. Run Flat tyres are designed to allow motorists, including those with electric vehicles, to continue driving up to 50 miles at up to 50 mph without loss of air pressure, even after most punctures. Run Flat technology is also expected to play an important role in future autonomous driving systems, by helping the vehicle remain operative in most road hazard events.
OVER 1,000 DIFFERENT VERSIONS DEVELOPED AND MORE THAN 70 MILLION RUN FLAT TYRES PRODUCED
Over the last 20 years, Pirelli’s engineers have developed more than 1,000 different types of tyres featuring run flat technology, which are built to allow drivers to keep driving for up to 50 miles at a maximum speed of up to 50mph. It’s a solution that has been adopted by many different manufacturers, who have requested run flat tyres as original equipment on their new vehicles – such as Audi, BMW, Mercedes-Benz and Alfa Romeo. Throughout these two decades, Pirelli has produced more than 70 million run flat tyres, including summer, winter and all-season tyres – some of which have been fitted to the most powerful and prestigious cars of recent times, including the entire BMW and Mini range, a substantial part of the Mercedes range, the Alfa Romeo Giulia, Audi Q5 and Q7.
A WIDE RANGE AVAILABLE
There are more than a dozen premium and prestige vehicle car manufacturers that use Pirelli tyres with run flat technology today, including Audi, Alfa Romeo, BMW, Jeep, Mercedes-Benz and Rolls-Royce. This technology is available on more than 50 models of Pirelli tyres homologated as original equipment for use by car vehicle manufacturers. All these tyres carry ‘run flat’ markings on the sidewalls, together with markings denoting the individual vehicle manufacturer they are intended for. On some tyres, this technology is combined with Pirelli Elect and PNCS noise-cancelling technology. The former is dedicated to electric vehicles and is focused on low rolling resistance, reduced tyre noise, grip, and a structure designed to support the weight of a battery-powered vehicle. PNCS is instead focused on reduction of perceived tyre noise inside the cabin, thanks to the use of special sound-absorbing sponge on the inside of the tyre. Pirelli Seal Inside is yet another technology made available by Pirelli. In the event of a puncture in most portions of the tyre, a sealing substance inside the tyre forms a seal around the foreign object as soon as it penetrates the tyre, preventing air from escaping and the tyre from losing pressure. When the foreign object is extracted, the same material seals up the edges of the resulting hole, until the tyre can be repaired, so drivers can carry on driving in control and comfort.
Pirelli’s high-end Run Flat tyres are the result of Pirelli’s innovative MIRS production process, which is entirely controlled by computer with ‘raw’ tyres made using robots offering a final result with high standards of quality and reliability. Pirelli’s self-supporting run flat system uses special reinforcements inserted into the internal sidewalls, which are designed to sustain the lateral and transversal loads on the car even in the absence of tyre pressure.
