Michelin CGDE : and Renault Sport look to the future of single-seater racing

In October 2014, Michelin and Renault Sport announced their intention to join forces to develop 18- and 17-inch diameter tires for the Formula Renault 3.5 and Formula Renault 2.0 single-seater racing cars that star in the WSR (World Series by Renault).

The decision came after a positive test at Jerez, Spain, which encouraged the two partners to continue down this road. Today, following further testing, Renault Sport and Michelin have concluded that the replacement of the 13-inch tires that currently equip the WSR's FR3.5 and FR2.0 cars by 18- and 17-inch tires respectively is a first class solution to make driving more enjoyable still for competitors. Benefits include enhanced performance during transient phases. Tires with smaller sidewalls produce less yaw, greater precision and improved steering response. At the same time, the change marks a big step forward in terms of the opportunities it offers when it comes to carrying over technology to Michelin road tires.

Ever since the pioneering days of the sport, motor racing has been seen as an important testing and development laboratory for technologies that go on to be used for road car tires. Michelin has long adhered to this philosophy and uses all the disciplines in which it is active to collect technical data that its Research and Development experts can dial into new, ever better-performing and increasingly efficient tires.

The World Series by Renault features two single-seater championships which are reputed for revealing talented upcoming drivers. They are the Eurocup Formula Renault 2.0, which is open to drivers as young as 16 years old, and the Formula Renault 3.5 Series which stands out as a benchmark series for the grooming of future Formula 1 drivers.

The conclusions of Michelin and Renault Sport with regard to the use of bigger-diameter tires eloquently illustrate the innovative philosophy that drives the two companies who, as leaders in their respective fields, have their sights set firmly on the future.

Testing resulted in the following sizes for the future being selected:

Today Tomorrow

FR3.5 (front slick) 26/64x13 --> 28/71x18

FR3.5 (rear slick) 32/66x13 --> 33/71x18

FR2.0 (front slick) 20/54x13 --> 20/61x17

FR2.0 (rear slick) 24/57x13 --> 24/64x17

'There are solid grounds from both the technical and sporting viewpoints for switching to 18- and 17-inch tires,' notes Philippe Mussati, Manager of Michelin Motorsport's Customer Competition Department. 'Our tests reveal that the drivers benefit from more precise performance, while the change also provides the teams with additional scope for set-up work which would consequently have a far bigger influence on results. On top of all this, bigger tires also enhance the cars' look.

'Renault Sport and Michelin believe these new tire sizes represent the future of single-seater racing. Any decision to use them for the World Series by Renault from 2016 will only be made once the development programme has been completed, but the perspective of Michelin being behind such a ground breaking shift in the world of single-seater racing in association with its long-time partner Renault Sport is an additional source of satisfaction for us.'

'We first proposed the change to the FIA [Fédération Internationale de l'Automobile] in 2010 when there was a possibility of our returning to Formula 1. The proposition wasn't taken up at the time. The chief reason why we want to switch to 18-inch tires is that they permit the development of new technologies that can be used for mass-produced road tires. We believe it is impossible to transfer technology from small-diameter tires with tall side walls, yet motorsport can play a significant role in speeding up the development of future road-going solutions. We need racing tires to have a similar profile to road tires to be in a position to develop new technologies.'

'Formula 1 is a different sort of spectacle. The cars have no need to resemble what you see in the street. Staying with 13-inch tires is a form of treading ground. Formula 1 has successfully become more modern in many areas but it is not a hotbed of innovation in the realm of tires. Single-seater cars racing on 13-inch tires are a thing of the past.'

'In addition to the technology-related considerations, bigger-diameter tires provide single-seater racing cars with a more modern look. At the same time, the gain for drivers notably concerns cornering performance. Without making any special effort to fine-tune car set-up, the early testing we carried out last autumn with Renault Sport at Jerez, in Spain, revealed that the cars were faster and far more enjoyable to drive simply after replacing the 13-inch tires with 17- or 18-inch tires.'

'I think the idea is gaining ground. The next decisions on the matter will be made at the end of 2015 for a possible introduction in 2017. Given that the new Formula E Championship cars use 18-inch tires already, and that promotional formulae like the World Series by Renault's FR3.5 and FR2.0 championships which prepare for Formula 1 are perhaps going to follow suit, it seems to me that it's a move that makes sense.'

'A 13-inch tire with a very tall sidewall contributes to a car's damping. The change to 18-inch tires with a smaller sidewall would certainly require a comprehensive revision of the cars' suspension systems.'

'We would study every aspect before coming to a decision. Let's just say that having cars on 18-inch tires would be a step down that road…'