In their latest combined test, the German and Austrian automobile clubs ADAC and ÖAMTC (1) compared various summer and winter Bridgestone Run-Flat Technology (RFT) tyres with the corresponding conventional tyre models from Bridgestone (2).
Tests were carried out on a BMW 1-series with tyre size 205/55 R16 H and V/W (3), and a Golf VI with tyre size 225/45 R17 W (4). Test criteria included braking and handling on dry and wet surfaces, mechanical comfort, fuel consumption and breakdown run ability; in the case of winter tyres, this also included braking and traction on snow and ice as well as handling on snow.
Experts considered that Bridgestone RFT tyres can now match conventional Bridgestone tyres completely in all areas. “The tested Bridgestone models show considerable improvements in comfort and rolling resistance, particularly in comparison to previous generations [in the ADAC Test 2002]. In these areas, there is not a lot of difference anymore with conventional tyre models without reinforced sidewalls.”
So actual tyres with Run-Flat Technology don’t have any significant disadvantages and in some cases, there were even signs of advantages in comparison to conventional tyres on wet surfaces In Germany, on a yearly basis, more than 2000 accidents happen – some of them lethal – due to tyre-related issues. It is clear that with RFT tyre-equipped cars, that figure would drastically go down. On top of that, RFT tyres also offer “peace of mind”. Today, over half of new cars are equipped with tyre repair kits which often do not work or are not able to repair tyres with big holes or cuts.”
Clear benefits for the consumer
Bridgestone RFT tyres have emergency features which allow them to retain their function even in the event of a puncture so that it is possible to continue driving safely, at a prescribed speed, until reaching the next workshop.
This provides drivers with a decisive advantage when it comes to safety: a puncture whilst driving with conventional tyres could result in loss of control of the car and – worst case scenario – cause an accident. In addition, drivers are spared the problems of a wheel change on a narrow or busy road or having to stop in dangerous areas. The use of RFT tyres not only reduces the danger of accidents, but it also means that it is no longer necessary to have a spare tyre on board.
The special sidewall reinforcement and an innovative and extremely heat-resistant rubber mixture (NanoPro-TechTM) enable tyres with Run-Flat Technology to remain stable. A reinforced bead core also ensures that the tyre is seated securely on the rim – even in the event of a complete loss of air pressure. As a consequence, the vehicle can be driven for at least another 80 kilometres at speeds of up to 80 kph (depending on load and vehicle).
In the ADAC/ÖAMTC test, all of the Bridgestone tyre models with Run-Flat Technology were able to continue driving for another 120 kilometres after complete loss of air pressure. Conventional tyres barely ran three kilometres.
Key focuses for Bridgestone’s product development: mobility and safety
Providing enhanced safety and mobility has always been at the heart of Bridgestone to accompany its customer’s journey. More recently, further innovations in that direction have been introduced, but RFT tyres have remained a pillar in that strategy for the past 14 years.
José Enrique Gonzalez, Director Consumer Marketing, Bridgestone Europe, describes the importance of RFT tyres for the company as follows: “Tyres with Run-Flat Technology are very important for the company but even more so for the end-user. These ADAC and ÖAMTC tests clearly show that enormous progress has been made versus the original RFT tyres from the late nineties: not only in terms of comfort but almost in all performance areas. Consequently, our latest tyre with Run-Flat Technology performs as well as a conventional tyre. This was also translated in an increase in sales, both in the original equipment and replacement markets. In original equipment BMW and Mercedes are the main car manufacturers who apply RFT tyres with our latest technology. Regarding the replacement market, this tyre concept has become increasingly popular which translates in a sales increase of 39% over the last 3 years (2009 to 2012). We believe that for the next 5 years, the market for tyres with Run-Flat Technology will continue to grow by 23%.”
1 Test results published by ADAC and ÖAMTC on 18th April 2013.
2 Summer and winter tyres with BMW factory fitment specification, as well as summer tyres for the after-sales market without manufacturer’s specification.
3 ER300 Ecopia RFT and Standard, LM32 RFT and Standard
4 S001 RFT and Standard