Formula One teams spend hundreds of millions on aerodinamics and engine development, but tyres are still a race car’s biggest performance variable that can easily influence its behavior.
The average car with good tires can be good, even very good, but even the best car with bad tires has no chance. Single tire manufacturer reintroduced in 2007. simplified the equation, but the optimization of the car in relation to the tyres in order to get the most out of them is still a major challenge for the engineers and the drivers.
Road and racing tyres maybe look similiar, but they construction, weight, performance and price are in different league. Road tire is made of heavier materials with durability as the primary objective (average road tire withstand more than 20 000 km). Rubber for a Formula 1 car is made to withstand a maximum of 200 kilometers and – like everything else on the Formula 1 – it must be as light and strong as possible. Complex nylon-polyester structure enable them to withstand much larger forces than on the road cars. In Formula 1 it’s more than 1500 kg of downforce, more than 4 g of lateral acceleration (cornering) and more than 5 g on braking.
Racing tire is made from very soft components that offer best grip on the race track, but wears very quickly. If you look at the race track after the race, outside the racing line you will see a large amount of marbles. Also, Formula 1 tyres give their maximum adherence at very high temperatures and in a fairly narrow temperature range (depending on the components, between 90 and 110 degrees Celsius). Also, the cars leave the garage with pre-heated tyres using electric tyre blankets which give drivers instant grip.
Racing tyres development began in 1960s when teams started to use slick tyres – they realised grip will increase with bigger contact patch and they were used in Formula 1 until 1998. when grooved tyres were introduced to limit cars’ performance.
Big rules change in 2009. brought slick tyres back in Formula 1 to increase amount of grip from tyres and decrease amount of aerodynamic grip generated by floor and wings.
From 2011. Pirelli is official Formula 1 tyre supplier and from 2016. they bring three different dry tyre compounds to each Grand Prix weekend.
Compounds can be identified by color of ‘Pirelli’ logo on their sidewalls: purple ultra-soft is softest compound introduced in 2016., followed by red super soft, yellow soft, white medium and orange hard compound.
Formula 1 cars will have 25% wider tyres than in 2016. – 305 mm front and 405 mm rear – and diameter of wheel remains 13 inches. Diameter of dry tyres is 660 mm, wet tyres 670 mm.
During Grand Prix weekend each driver has 13 sets of dry weather tyres, 4 sets od intermediate tyres (less water on track) and 3 sets of wet weather tyres (a lot of water on track).
From 13 sets of dry tyres Pirelli will choose 2 mandatory sets for the race (two harder compounds, drivers must use at least one of them) and 1 set specially for Q3 (softest of three avalaible compounds). If driver doesn’t qualify in Q3 he may use that set in the race.
Drivers choose remaining 10 sets of dry weather tyres within three avalaible compounds and they have to make their choices at least 9 weeks before race in Europe and at least 15 weeks before race outside of Europe.
For the first five races od 2017. all drivers will have same avalaible compounds because drivers who tested 2017. tyres in 2015. mule cars od Mercedes, Red Bull and Ferrari could have the advantage so FIA decided to level things out.
The softness of certain components of the tyre changes depending on the quantity of certain ingredients that make up the mixture, and the main three ingredients are carbon, sulfur and oil. Generally speaking, the more oil in the tyre, the tyre will be softer.
Intermediate and wet tyres have patterns on the tread surface, which are necessary in order to eject the water in wet conditions and enable tyre to make a contact with the road. If tyre can’t pump water fast enough to make that contact ‘aquaplaning’ can occur, when a layer of water between rubber and asphalt makes car floating above the track and drivers can lose control easily. Intermediate tyres are designed to pump out fewer liters of water per second than wet tires, which makes them more suitable for situations with less water on track.
Tyres in Formula 1 are filled with a special mixture of air and nitrogen to minimize variations in pressure with temperature change. A mixture also hold the pressure better than air itself.