Why they stop
The main reason is to change tyres. As we saw in the article on tyres, they wear and lose speed lap by lap. Also, in a dry race drivers must use two different types, so stopping at least once is mandatory.
Since 2010 no refuelling is allowed during the race. The car sets off with all the fuel it will use to the finish. A stop can also be used to repair a broken wing or to serve a penalty.
What happens in those two seconds
Each team has its own marked place in front of the garage. The driver must brake exactly on that mark, because an error of a few centimetres loses time. This is what happens, nearly all at once:
- Two jacks lift the car, one at the front and one at the rear.
- Several mechanics work on each wheel: one loosens the nut, another takes the wheel off and another puts the new one on.
- When all four wheels are ready, a system of lights tells the driver they can go.
- The car drops and the driver pulls away, without hitting anyone in the pit lane.
A very good stop lasts about 2 seconds. One of the fastest on record was by McLaren, at 1.80 seconds in Qatar 2023. A stuck wheel nut, on the other hand, can cost 10 seconds or more.
The time shown on screen is only the time the car is stopped. The real loss is far greater.
How much time is really lost
A 2-second stop does not cost 2 seconds. You have to add the time spent slowing down, driving the whole length of the pit lane and getting back on track.
In the pit lane the limit is 80 km/h, while on the straight cars go over 300 km/h. In total about 20 seconds are lost, and this varies quite a lot by circuit. The longer the pit lane, the more expensive the stop.
That number is the basis of all strategy. If a rival is less than 20 seconds behind, when you stop you will come out behind them. That is why you see so much gap calculation on TV.
If a driver goes over the speed limit during the race, the stewards can penalise them. The penalty ranges from 5 seconds to a stop-and-go, depending on how far over they were.
The undercut: stopping before your rival
This is the most famous move. If you are behind a car and cannot pass it on track, you pit before it does. On new tyres you lap much faster for a few laps. When your rival stops, you come out ahead.
It works best at circuits where new tyres make a big difference. It also requires a clear track when you leave the pits. If you drop in behind a slow car, you lose the whole advantage.
The overcut: stopping later
This is the opposite. You stay out when your rival stops. If your tyres are still working and the other driver comes out into traffic or takes a while to warm up the new ones, you gain time and come out ahead when it is your turn to stop.
It tends to work when new tyres take time to grip, for example in the cold, or when the rival comes out behind slow cars.
Safety car: the cheap stop
When the safety car comes out, the cars on track go much slower. Pitting at that moment costs far less, sometimes half, because rivals cannot get away.
That is why, as soon as the safety car appears, you see nearly everyone pitting together. Whoever stopped just before feels very unlucky: they paid the full price and the others do it almost for free. It is one of the big doses of luck in F1.
Under a red flag something similar happens, and it is even more generous. While the race is stopped, teams can change tyres in the pit lane without losing time.
A driver cannot serve a drive-through or stop-and-go penalty while the safety car or virtual safety car is on track.
Double stacking: two cars, one place
A team's two cars share the same pit stop place. If both need to stop at once, the second must wait in line until the first is done. This is called a double stop, or double stacking.
It goes well if the two cars are a few seconds apart. It goes badly if the second one loses a lot of time waiting. It is one of the riskiest moves for the mechanics, because every second counts.
How it looks on TV
When you hear "box, box" on the radio, the engineer is telling the driver to come in on that lap. If they are told "stay out", the plan has changed.
Mechanics coming out of the garage with tyres are the best clue. If they appear, someone is coming in soon. Teams often send their mechanics out and then call them back, just to confuse a rival and force a reaction. You can also see on screen the gaps between cars, which tell you whether a stop will work.
Each team practises pit stops hundreds of times a year, even at the factory and during the race weekend itself. Before the race you can see several rehearsals in the pit lane, and small gains in each step are analysed on video.
How many stops are made
- One stop
- Less time is lost in the pits, but the tyres need a lot of care.
- Two stops
- More time is lost in the pits, but the tyres are fresher and the car goes faster.
- Three or more
- This is less common. It tends to happen on circuits that are very hard on tyres or because of the unexpected.
The sum is simple. If stopping once more costs you 20 seconds, but the new tyres give you a 25-second advantage by the finish, it is worth stopping. Teams do that sum live with thousands of simulations.
Rules and common mistakes
- Unsafe release: a car cannot be let go if it puts another car, or someone in the pits, at risk. If it happens, there is a penalty.
- A badly fitted wheel: if the car leaves without the wheel properly secured, it must stop and there can be a penalty.
- Reversing: a car cannot reverse under its own power in the pit lane. If it overshoots the mark, the mechanics have to push it back.
- Serving a penalty: the 5 or 10 seconds are waited out standing still, before anyone touches the car.
- Speed: the 80 km/h limit can be lower at circuits where the pit lane is very narrow.
Frequently asked questions
Who decides when to stop?
The team's strategy wall, with the driver giving an opinion on the radio. Many experienced drivers ask to stop earlier or later depending on how the tyres feel.
Can you win without stopping?
In a dry race, no. You have to use two types of tyre. In a wet race or a sprint, yes.
How many people work on a stop?
There are about 20 mechanics at each stop, trained to repeat the same movements hundreds of times a year.