F1 Tyre Compounds C1-C5: Pirelli Range and Strategy

The compound range explained

Pirelli produces five dry-weather tire compounds for Formula 1, numbered C1 (hardest) through C5 (softest). For each race weekend, Pirelli selects three of these compounds and labels them hard (white sidewall), medium (yellow), and soft (red). The actual compounds used vary by circuit — a C3 at Monaco might be the hardest compound available, while the same C3 at Silverstone might be the softest.

C1 and C2: the hard compounds

C1 and C2 are the hardest compounds in Pirelli's range. They are used at high-speed, high-load circuits like Silverstone and Spa, where softer compounds would degrade too quickly. They offer less grip but much better durability, making them ideal for long stints.

C1 is the hardest tyre Pirelli produces. Its operating window starts at a higher surface temperature — typically above 120°C — which means it takes longer to warm up in qualifying but maintains its performance for 30 laps or more at demanding circuits. At the 2024 British Grand Prix, Lando Norris ran a 28-lap stint on the hard compound (C1) with only a 0.4-second drop-off in lap time across the entire run. That consistency is why teams favour the hard compound at circuits with high lateral loads and abrasive surfaces.

C2 is marginally softer and more versatile. It appears at more race weekends than any other compound because it sits in the middle of the grip-durability trade-off. At the 2024 Bahrain Grand Prix, the C2 served as the medium compound and became the race-defining tyre: teams that managed its thermal window well could stretch a one-stop strategy, while those that pushed too hard early saw graining appear by lap 15. Ferrari's Carlos Sainz ran a 24-lap first stint on the C2, managing his pace carefully to avoid the cliff — the point at which degradation accelerates sharply and lap times drop by 1-2 seconds in a single lap.

C3: the middle ground

C3 is the most versatile compound. It is used at circuits that are neither extremely demanding nor particularly gentle on tires. It offers a good balance between grip and durability, making it the most commonly selected compound across the season.

The C3 appears at nearly every race weekend, either as the soft, medium, or hard compound depending on the circuit. At Monaco, where top speeds are low and mechanical grip matters most, C3 might be the hardest available compound. At Monza, where aerodynamic efficiency dominates, the same C3 could serve as the softest option. This flexibility is what makes it the backbone of Pirelli's range.

Max Verstappen has spoken about the C3's predictability: "You know what you are going to get with the C3. It does not surprise you." That predictability is precisely why strategists like it — the degradation curve is well understood, the thermal window is forgiving, and the crossover point between it and adjacent compounds is consistent. At the 2024 Spanish Grand Prix, the C3 served as the medium compound and was the race tyre for the majority of the field, with most teams running two-stop strategies built around 18-20 lap stints before switching to a fresh set.

C4 and C5: the soft compounds

C4 and C5 are the softest compounds, offering maximum grip but degrading quickly. They are used at street circuits like Monaco and slow, twisty circuits like Hungary, where mechanical grip is more important than durability. These compounds are typically used for qualifying and short race stints.

C4 delivers strong single-lap performance and appears at most race weekends as the soft or medium compound. Its operating window sits around 90-110°C, which means it warms up quickly and delivers peak grip within two or three corners. That fast warm-up is why it dominates qualifying: drivers can push immediately without needing preparation laps. But the trade-off is steep — at high-energy circuits like Silverstone, the C4 can lose up to 1.5 seconds per lap after just 10 laps as the surface overheats and the tread begins to grain.

C5 is the softest tyre in Pirelli's range and the most extreme. It is reserved for circuits where mechanical grip dominates and tyre energy inputs are low. Monaco, Singapore, and Hungary are its natural homes. At the 2024 Monaco Grand Prix, Charles Leclerc qualified on the C5 and described the grip as "incredible for one lap, then it starts to go away." The C5's window is narrow: too cold and it slides, too hot and it melts. Engineers typically measure its peak performance window at just 15-20°C of surface temperature range, compared to 30-40°C for the C1. That fragility is why teams rarely race on the C5 unless the strategy demands it — a short sprint stint or a late-race gamble on fresh rubber.

The 2026 change: C6 removed

For 2026, Pirelli removed the C6 compound from the range, leaving C1-C5 as the full spectrum. The C6 was extremely soft and was only used at a handful of circuits. Its removal simplifies the compound selection process and reflects the fact that the 2026 cars, with less downforce, put different demands on tires.

The C6 was introduced as an experiment to provide an ultra-soft option for the slowest circuits, but it proved problematic. Its thermal window was so narrow that even small changes in ambient temperature could push it out of the operating range. At the 2025 Monaco Grand Prix, several drivers reported that the C6 was "switching off" mid-stint — losing grip suddenly rather than degrading gradually. Pirelli's motorsport director, Mario Isola, acknowledged that the compound "worked in a very narrow window and was not giving us the consistent performance we wanted."

With the 2026 cars generating less aerodynamic downforce, tyre energy inputs will change across the board. Lower downforce means less vertical load on the tyres, which in turn means lower surface temperatures and a different degradation profile. Pirelli designed the C1-C5 range to work within this new envelope, with each compound recalibrated to maintain its relative position in the grip-durability spectrum while tolerating the changed thermal environment.

How compound choice shapes strategy

The compounds Pirelli selects for each weekend fundamentally shape race strategy. A weekend with C1-C2-C3 will produce races with fewer pit stops and less variation between strategies. A weekend with C3-C4-C5 will produce races with more pit stops, more overtaking, and more strategic variation.

Teams must decide how many of each compound to use during the weekend. In qualifying, they want the softest compound for maximum grip. In the race, they must balance grip against durability, knowing that a tire that is too soft will degrade before the end of the stint.

The strategic mathematics are more complex than they appear. Each driver must use at least two different compounds during a dry race, which means every strategy involves at least one pit stop. But the timing of that stop — and whether to add a second or even third stop — depends on the degradation rate of each compound at that specific circuit, in that specific weather, on that specific car.

At the 2024 Hungarian Grand Prix, the C3-C4-C5 selection produced a strategic chess match. Verstappen started on the medium (C3) and stretched his first stint to 28 laps, building a tyre offset that allowed him to attack on fresh softs in the final stint. Norris, on the same compound, pitted five laps earlier and emerged in clean air — a classic undercut attempt that nearly worked. The gap between their strategies came down to 1.7 seconds at the flag, showing how compound selection and stint timing interact at the margins.

Teams also account for tyre allocation rules. Each driver receives 13 sets of slick tyres for the weekend: two hard sets, three medium sets, and eight soft sets. How they distribute those sets across practice, qualifying, and the race is itself a strategic decision. Running too many softs in practice leaves fewer fresh sets for qualifying; saving mediums for the race may mean running an older spec in FP2. Red Bull's head of race strategy, Hannah Schmitz, has described this allocation planning as "one of the most important decisions of the weekend, and it happens before anyone turns a wheel."

Where Fans Get Confused

C1 to C5 is not a simple ladder where the softest tyre is always fastest and the hardest tyre is always safest. Track temperature, surface roughness, car balance and stint length can make the same compound look aggressive at one circuit and conservative at another.

Watch the first push lap, the second push lap and the final five laps of a stint. If the tyre is slow to warm up, the undercut may fail. If it overheats quickly, early pace can become a trap. Compound names only matter once you connect them to the working window.

F1 Tire Compounds: C1 to C5 Deep Dive