Pirelli unveiled the technical specifications of the new summer tires launched on the market this year.
In 2020, Pirelli released a new passenger-car summer tire model Pirelli Cinturato P7, which came to replace the predecessor model of the same name, and which differs from it with a P7C2 code and a whole number of new innovative features.
The previous-generation model, presented in 2009, has become one of the market leaders when it came to the number of car models, for which it was chosen as original equipment, and all this time its performance has been steadily improved due to close cooperation between this tire manufacturer and major car makers. The new-generation tire model, according to Pirelli, has been improved in both key areas of today’s concern — safety and environmental performance. As the tire maker claims, its R&D experts were able to create a high-technology state-of-the-art product that was able to avoid compromises, hitherto common for the tire industry. Specifically, due to the technologies used in the production of the Cinturato P7, the designers were able to reconcile such generally conflicting factors as strong grip on wet pavement and low rolling resistance, and this balance will obviously be important both for end users and for car makers looking to cut down the carbon emissions from their new models.
Even though the issue of ecology is as relevant as ever, the main consideration in making tires is still driving safety, and this fully applies to Cinturato P7. According to the developers, the new model ensures the dry traction level of its predecessor but significantly outperforms the previous-generation model in terms of handling response on wet pavement. The tire also has a lower rolling resistance; particularly improved was the wet braking performance, and, as Pirelli claims, the stopping distance from 100 km/h on water-covered surface was reduced by 4 meters. The new technical solutions also helped to improve the acoustic comfort and the tire’s ability to absorb shocks when driving on uneven roads. In addition, the tread life was increased by 6%, which will allow the drivers to have their tires replaced not as often, while the rolling resistance was cut by 12%, which is equivalent to the same class on the EU labels.
One of the main factors that determine the performance of any tire is the tread compound. For the Cinturato P7, a new rubber compound was developed, with a high content of silica and special resins, whose task is to enhance the traction, as well as with functionalized polymers, i.e. chemically modified elastomeric materials that facilitate the interaction between the silica and the other elements of the compound. What makes these polymers special is their ability to behave differently at different temperatures. Due to this, the compound, which is also characterized by a better dispersion of silica particles, received a semblance of «mechanical intellect» that helps the tires to adapt to the current weather, maintaining the optimum traction in a very wide range of temperatures.
As for the tread pattern, each of its elements performs its own function — from the longitudinal and lateral grooves, whose geometry was changed for better evacuation of water from the contact patch, to the shoulder lugs, whose design was specially developed to reduce the stopping distance on dry, but, above all, on wet pavement. In addition, the tread design and rigidity distribution have been optimized for more stable cornering, while the varying pitch of the tread — it was initially created in cyberspace, and then subjected to numerous tests — reduces noise emission and ensures a smooth noiseless ride.
The new materials used in the tread compound also increased its mechanical strength, at the same time ensuring a better grip in various road situations. The increased resistance to wear made the tire more durable, and this was achieved through the use of high-polymeric substances. Effectively, this means that due to the long molecular chains, the mechanical properties of the compound, such as abrasion resistance and sturdiness, are improved. Pirelli adds that the rubber compound was being developed concurrently to the tread pattern, which further ensured their better functionality.
Increasing the mechanical strength of the compound allowed the developers not only to extend the tire’s tread life but also to reduce the sheer amount of materials necessary for their production, which helped to make the tire lighter. The reduction of weight, in turn, served to decrease the rolling resistance, leading to more efficient fuel consumption, thus improving the tire’s environmental performance. Pirelli also focused on improving the reinforcement materials, the use of heavy-duty steel wire, for example, making it possible to reduce the number of strands, and, consequently, the weight of the undertread band. We can only add that weight reduction is one of the key requirements that car makers pose to tire manufacturers.
Yet another issue that the Pirelli engineers addressed is the «dialogue» of the tires and the advanced driver assistance systems (ADAS). For example, Pirelli states that due to the optimized tread pattern the tires will better interact with the ABS and reduce the braking distance compared to tires of the same size installed on the same car. It is noted that the collaboration with car makers, including the digital simulation of tires, allows the advanced driver assistance systems to function to maximum efficiency. This means, for example, that the lane keep assist system (LAS) better works with the tires whose specifications were taken into account in the calibration process as opposed to «unknown» tires. In the latter case, the system will need extra time to correct the direction of movement because it will not be able to predict how the tires will behave. If, however, the behavior of the tires that were specially adapted for this or that specific car model will be comprehensible and predictable for the system, less corrections will be required.
The Cinturato P7 line will include both tires made with the latest Pirelli technologies and the ones that will be adapted to individual car models or user groups. For example, the recently-developed Elect technology will be implemented. Tires bearing this sign are designed for electric and hybrid cars and have a number of new features, such as ability to ensure maximum traction at the very start of the driving combined with maximum momentum, and low rolling resistance, which increases the driving range without having to recharge the batteries, and ensures low noise emission, further enhancing the riding comfort delivered by noiseless electric cars. In addition, the company will roll out new tires that utilize the Run-Flat and Seal Inside technologies that make it possible to continue driving in the event of a puncture due to the reinforced sidewalls and the sealant layer in the construction.
It took the company about three years to develop the new Cinturato P7 model, and, before it was launched on the aftermarket, it was already 70 times certified by various car makers; it is expected that by the end of the year this figure will exceed 100 homologations. Pirelli notes that in comparison to the predecessor model, there is a marked increase in the number of homologated tires with a 17-inch fitting diameter, which testifies to their popularity among the high-end car makers.