A puncture is one of the most feared situations for drivers. Not so much for the damage itself, but for the consequences: stopping on a motorway, changing a tyre in difficult conditions, or being stranded far from a garage. That is why Pirelli has developed several technologies designed to ensure continued mobility even when tyre pressure drops to zero. Three solutions are available: Run Flat, RunForward and Seal Inside. “We are talking about three puncture-resistant technologies with different philosophies”, explains Alberto Maria Putti, Pirelli Marketing Product Manager. “They all share the same goal: to allow the driver to continue driving safely even after a loss of pressure, avoiding potentially dangerous situations”.
Run Flat, safety even at zero pressure
Run Flat technology, developed to enable continued driving after a puncture, integrates specific reinforcements within the tyre sidewall, capable of supporting the vehicle's weight even in the complete absence of internal pressure. “Inside the sidewall there are high-rigidity structural elements, engineered to provide load-bearing capacity and resist severe deformation”, explains Putti. “These reinforcements come into action as soon as a pressure loss occurs, making it possible to maintain vehicle stability and control”. Thanks to this solution, drivers can continue travelling for a limited distance, up to 80 kilometres at a maximum speed of 80 km/h, enough time to reach a garage or return home safely. “The goal is to offer an escape function, meaning the ability to get out of a potentially critical situation without having to stop immediately”, Putti clarifies.
RunForward, theevolution for next-generation vehicles
RunForward, a more recently introduced technology, was developed to meet the needs of next-generation vehicles, particularly electric cars. "Modern vehicles are increasingly heavy and often have no space for a spare tyre", explains Putti. "RunForward was created specifically to provide an extended mobility solution without compromising the key characteristics of these new vehicles, such as comfort and efficiency”. Here too, the underlying principle is supporting the vehicle's weight through sidewall reinforcements, using next-generation materials. "The new compounds are engineered to reduce heat generation and internal stress, enabling the use of efficient reinforcements that are always capable of bearing the load acting on the tyre in the event of a sudden pressure loss", Putti continues. "This translates into improved driving comfort and very low rolling resistance levels”. The result is a tyre capable of continuing to run for up to 40 kilometres at a maximum speed of 80 km/h with no pressure, while at the same time delivering, under normal conditions, a driving experience equivalent to that of a conventional tyre.
Seal Inside, the technology that seals the puncture
Alongside these solutions, there is a third technology that addresses the puncture problem from a completely different angle: Seal Inside. In this case, the tyre is not designed to bear the vehicle's weight at zero pressure, but rather to prevent pressure from being lost in the first place. “Insidethe tyre, beneath the tread, we apply a layer of sealant material”, explains Putti. “If a sharp object such as a nail pierces the tyre, this material wraps around the foreign body and prevents theair from escaping”. When the object is removed, the sealant automatically fills the hole, sealing the puncture and allowing the driver to continue without stopping. “Seal Inside technology is capable of covering approximately 85% of the possible accidental causes of pressure loss,”, adds Pirelli's Marketing Manager, highlighting how the system works without requiring specific rims or additional components.
Different technologies, one shared goal: safety
Three different approaches, then, to tackle the same problem. "There is no single best solution", concludes Putti. "It depends on the driver's priorities: some prefer maximum range when running at zero pressure, while others favour a solution like Seal Inside. Our goal is to offer different technologies to meet all these needs". Because when it comes to road safety, true innovation means being able to continue the journey, even when something goes wrong.
