A pit stop looks like chaos but is one of the most rehearsed routines in sport. Get it right and a driver loses barely 20 seconds of track time; get it wrong and a race can unravel in the pit lane.
The stop itself
A crew of around 20 people swarms the car. Four pairs of mechanics handle the wheels, each running a wheel gun that loosens, removes and refits a tyre in a blur; others steady the car or work the front-jack and rear-jack. The wheel change itself takes roughly two to two-and-a-half seconds, with the total time loss mostly coming from the slow drive down the speed-limited pit lane. The “stop” you hear timed on the broadcast is just the stationary part.
The two-compound rule
In a dry race, every driver must use at least two different dry tyre compounds. That single rule is why nobody can simply bolt on one set and drive to the flag; at least one pit stop is effectively mandatory. (In a wet race declared by the stewards, that requirement is waived.)
The pit window and strategy
The pit window is the range of laps in which a stop makes sense: late enough that the new tyres last to the end, early enough that the old ones haven’t fallen off a cliff. Teams plan one-stop or two-stop races around it, balancing fresh-tyre pace against time lost in the lane.
The timing of a stop relative to a rival is where strategy gets interesting. Pit before an opponent and use fresh-tyre pace to leapfrog them: the undercut. Stay out longer and rely on clear air to build a gap first: the overcut. Both are explained in full, with a worked example, in the overtaking guide.