Written by Benjamin Crundwell, Edited by Jann Erin Castro
The most fundamental ability of any car is it’s ability to move forwards. This would not be possible without the carefully and cleverly engineered pieces of rubber we call tyres — and in Formula One, tyres play a crucial role. Continue reading below to know more about them.
Pirelli: Formula One’s exclusive tyre supplier
Since 2011, Pirelli has been the sole provider of Formula One tyres, however their involvement in the sport stretches further back than that.
The Alfa Romeo Tipo 158, which won the first F1 race and championship in the hands of Italian driver Giuseppe Farina, was equipped with a set of Pirelli tyres.
41 races were won by Pirelli-clad cars during the 1950s, by far the most successful of any manufacturer.
Unfortunately, Pirelli did not design tyres again for F1 cars for over 20 years during the 60s and 70s.
Upon their return in 1981, Pirelli then went on to gain three more wins within the next decade. In 2011, Pirelli permanently returned to F1 and has since been its sole tyre supplier.
Throughout their rich history in the sport, Pirelli has been competing against other major tyre manufacturers such as Dunlop, Michelin and Goodyear, to name a few.
As of the 2024 season, Pirelli tyres have won over 300 F1 races, second only to Goodyear who have won 368. Additionally Pirelli has won 19 drivers championships and 13 constructors championships.
The basics
Contrary to the popular belief, there are actually five tyre compounds and not just the three commonly heard of compounds (soft, medium and hard).
Before understanding more of the compound specifics, the easiest way to identify slick tyres are its sidewalls — softs have a red sidewall, mediums have a yellow sidewall and hards have a white sidewall.
F1 currently uses 18-inch tyres, which took over 10,000 hours of indoor testing and 5,000 hours of simulation work to perfect.
Pirelli then picks three of the best compounds to be used on the weekend. As of 2023, the slick tyre compounds are defined as follows:
C0 – Hard (White) – The hardest tyre compound designed for maximum heat resistance and long-running stints but may cost peak performance
C1 – Hard (White) – Similar to C0 but still allows for peak performance
C2 – can be Hard (White) or Medium (Yellow) – Suitable for fast, hot and abrasive circuits; usually selected for new circuits
C3 – can be Medium (Yellow) or Soft (Red) – A versatile compound that can be considered hard, medium, or soft, and can withstand a wide range of conditions
C4 – Soft (Red) – Needs to be warmed up to reach peak performance and can be used in low-severity circuits
C5 – Soft (Red) – The softest tyre compound designed for slower circuits or street circuits; warms up faster but also degrades faster
The C3 tyre is the most commonly used tyre across race weekends, even having run over 107,000 km within the 2024 season. The C4 is the second most used tyre in 2024, with over 78,000 km recorded.
One common question F1 enthusiasts usually ask goes along the lines of: “The soft tyre is already terribly worn out after one qualifying lap and the hard tyre can go 30 laps into the race, how can this be the same tyre on different weekends?”
The answer to this comes from a combination of different factors.
For starters, a driver will push the car a lot harder on a qualifying lap, causing excessive tyre wear, unlike in a race where the driver is focusing on retaining the life in his tyres.
Furthermore, the compounds of tyres are picked based on the track's characteristics. For example, Silverstone puts a much larger load on the tyres than a track like Monaco, so harder compounds are chosen for the British Grand Prix.
The red sidewall soft tyre is run most commonly in qualifying because it bears the most grip, allowing cars to take corners faster and set quicker lap times. However the tyre will wear very quickly, making it only effective for a short period of time.
In some cases, the tyre will actually struggle to finish an entire lap, causing drivers to have to manage in the first sector so they will be able to extract more performance at the end of the lap.
The white sidewall hard tyre has far less grip, but it's selling point is it’s long-lasting qualities. Due to the tyre wearing slower than the soft tyre, if treated right it can last for over half the race distance.
In one extreme case, Alex Albon made his hard tyres last 57 laps in the 2022 Australian Grand Prix, only pitting on the penultimate lap because of the mandatory pitstop rule. Albon was still able to pull off a miraculous points finish with this strategy.
The medium tyre is represented by a yellow striped sidewall. The best way to describe it’s performance is to say “it’s in the middle” — the tyre has less grip than the soft, but more than the hard. It will not last as long as the hard, but it will last longer than the soft.
Occasionally, the medium tyre will make an appearance in qualifying, often when the soft tyre is struggling to finish the lap. However, the medium tyre is mainly used in the race and is often the standard tyre to start on.
Formula 1 uses two other compounds in wet and rainy conditions: the intermediates, and the full wets.
The intermediate (often referred to as the “inters”) is designed to have a wide working range, to guarantee a crossover window with both the slicks and the full wets. This is best for when a track is not fully wet but also not particularly dry.
In contrast, the full wet (often referred to as the “wets”) should be used when there is standing water and heavy rain. The wets are designed to withstand heavy rain conditions and help cars retain their grip on slippery tracks.
At 186.4 mph (300 kph), the wet tyre can disperse 85 litres of water per second. Unfortunately, the race is often red-flagged before the cars get onto the full wets, due to safety concerns over visibility and aquaplaning.
Tyre grip
The car’s only contact with the track at any point is through the tyres. They are solely responsible for creating a car which responds appropriately to the drivers requirements.
Effectively, the rest of the car is set-up to create the correct conditions for optimal tyre performance. There are two types of grip on a motor vehicle: aerodynamic grip and mechanical grip. Both of these methods work by increasing the friction between the tyre and track, as it reduces the sliding.
To further understand the effect yourself, imagine you are driving on an ice rink. When you try to turn, the car will simply continue moving forwards as the tyres have no grip on the slippery surface. Furthermore, once you can get the car to turn, it will want to over-rotate and spin.
By increasing the friction between tyre and track, you will get more response from turning the wheel and the car will be more reluctant to spin.
F1 cars' advanced aerodynamics create a downwards force (downforce) to push the car into the ground. This is called aerodynamic grip, but it is not instantly obvious how it generates grip.
Friction on the tyres (Nfriction) can be calculated by the force (F) pushing the tyres into the ground (the car's weight added to the value of downforce) multiplied by the coefficient of friction (COF; μ).
Nfriction = F μ
By increasing the downforce the friction force will also increase, providing the driver with more grip so they can drive faster through the corners.
Here’s another example: put your hand lightly on the wall and move it in a circle; then slowly push your hand harder into the wall. Upon applying a great force on your hand against the wall, you will notice that there is greater friction — your hand will not move about so easily.
The other form of grip is mechanical grip, teams can improve this by making adjustments to their car, such as ride height, suspension stiffness and toe angle.
Additionally, the tyre itself can be designed to optimise grip. Although, F1 teams get little influence on this factor as Pirelli designs the tyres for all teams to use.
As mentioned earlier, the soft tyre holds the highest grip. This is because it will have the highest COF, unlike the hard tyre which has the lowest.
For reference, the COF on a street car tyre is about 0.7 to 1.0, but on a racing car it will vary between roughly 1.7 to 1.9, twice as high!
Since friction is equal to the COF multiplied to the reaction force, the bigger COF results in more friction between the tyre and track, allowing the car to turn better.
For a tyre to work optimally, it must be in the correct tyre range. For the C1 tyre (hardest) this is in the range of 110℃ to 140℃, but for the C5 (softest tyre), it should be in the range of 85℃ to 115℃.
If the tyre is too cold, then the rubber will harden, making it difficult to grip onto the road. If the tyre is too warm, then the rubber will lose its structural integrity.
This is why during qualifying, the cars will take a lap (or sometimes two) to ensure their tyres are in the correct temperature window before doing a fast lap.
This is the same situation during the formation lap before the race. However, cars at the front have a disadvantage in this respect, because while they sit on the grid waiting for backmarkers to line up, their tyres are already cooling down.
Tyre wear and degradation
While the absolute pace of a car is important, it is nothing without a good tyre life. As the tyre gets older, it will lose grip, causing the car to become harder and slower to drive.
Tyre wear occurs when the tyre scrubs across the surface of the track, taking rubber off the surface. However, degradation is the effect of temperature on the tyre.
There are a few key terms you will often hear while watching F1:
Tyre graining – As the tyre slides across the track, the rubber starts to break up, leading to irregularities on the surface. This phenomenon most commonly occurs when temperatures are low. Fortunately, graining can wear away throughout the stint, so it is not a permanent loss in grip.
Tyre blistering – The inside of the tyre can overheat, causing pockets of hot air to form under the surface. Resultantly chunks of the surface rubber rip away from the tyre, leaving a “blister.” This will often occur when the tyre has been over-inflated or has been heated up too fast.
Flat spots – A lock up under braking will drag the tyre across the track, leaving a square edge on the tyre (to quote Martin Brundle: “like a 50 pence piece”). This leads to more lock ups as each time the driver presses the brake, and the tyre is most likely to rub the flat area of tyre on the track.
Flat spots will lead to heavy vibrations in the car and ruin the handling. In the 2005 European Grand Prix, a flat spot on Kimi Raikonen’s McLaren was strong enough to break the suspension.
There are three main causes of tyre wear: track surface, corner speeds and track temperature.
A rough surface will provide more grip, but also cause higher wear. Faster corner speeds and higher track temperatures will both lead to increased levels of wear, as the tyre deforms more.
This is why fast and flowing tracks with high temperatures, such as Qatar, have such extreme tyre wear.
In the 2023 Qatar Grand Prix, a rule had to be implemented that drivers could not exceed 18 laps on a set of rubber, or they would be disqualified. This was due to safety concerns — if a tyre is worn too much, it will cause a puncture.
Environmental Effect
Like all car components, the tyres can cause extensive environmental effects. However, Pirelli is a global leader in the war with climate change, being the first tyre manufacturer to receive a three-star rating on the FIA’s Environmental Accreditation Programme.
FSC (Forest Stewardship Council) certification ensures natural rubber plantations are run in a manner which benefits local communities and the biological surroundings.
In 2021, the Italian producer was the first company to introduce a complete range of FSC-certified tyres for motorsport.
In 2024, Pirelli started utilizing FSC-certified rubber for F1 tyres. All natural rubber in the European plants will be FSC-certified by 2026.
Pirelli is taking action on other initiatives to reduce their effect on the environment by using 100% renewable certified sources to generate the electrical energy required to make each tyre and optimising the use of “virtual” design, which reduces the volume of waste materials, as less physical prototypes are needed to be made.
After every race weekend, every tyre is taken to a recycling centre where it will be transformed into secondary raw materials.
Regulation
Despite each team being allocated the same tyres, there are still strong regulations in place to prevent any team from gaining an advantage.
From the five dry compounds discussed prior (C1, C2, C3, C4 and C5), only three will be chosen for a race weekend. The compounds taken to a track will be decided based on the track’s design and the climate over the course of the race weekend.
At each competition, each team will be allocated two sets of hard tyres, three sets of mediums, and eight sets of soft tyres per car. Each car will also have four sets of intermediates and three sets of wets available to them. Pirelli may provide more wet tyres if it is deemed necessary.
The previous rule is changed on a sprint weekend, when each car receives two sets of hards, four sets of mediums and only six sets of softs. Assuming the whole race is dry, it is mandatory that each car uses two different dry compounds during the race.
The most common choice of strategy is to start on the mediums and switch to the hards. However, occasionally, a team will try to start on hards so they can pit later and have fresher rubber at the end of the race.
Alternatively, in some races a two-stop may be the faster way to finish the race. Drivers will usually still start on the medium and then it is more varied which tyre they will choose for the latter stint.
If a driver does not comply with at least one tyre change, they will be disqualified from the race.
Under the circumstance that the race is suspended and cannot be re-started, the rules state that: “30 seconds will be added to the elapsed time of any driver who was unable to use at least two specifications of dry weather tyre.”
Although they may seem like simple parts of the car, tyres bear the complexity of science and strategy that help push the limits in F1.
Likewise, Pirelli considers the sport as its “open-air research and development laboratory,” that allows further innovations for everyday road tyres.
F1 and Pirelli have now been partnered for a decade and a half, constantly working to make improvements in lap time, entertainment and safety.
With the 2025 season just around the corner, you can now put your tyre knowledge into use as you watch each race, becoming your favourite driver’s stay-at-home strategist.
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