Pit stop
In motorsports, a pit stop is a pause for refuelling, new tyres, repairs, mechanical adjustments, a driver change, as a penalty, or any combination of the above. These stops occur in an area called the pits, most commonly accessed via a pit lane which runs parallel to the start/finish straightaway of the track and is connected to it at each end. Along this lane is a row of garages outside which the work is done in a pit box. Pit stop work is carried out by the pit crew of up to twenty mechanics, depending on the series regulations, while the driver often waits in the vehicle.
The term is also used generically to describe a short break in a journey.
Location and terminology
Depending on the circuit, the garage may be located on pit lane or in a separate area.In most series, the order of the teams' pit boxes is assigned by points standings, race results, or previous qualifying results before the start of the race. In NASCAR and in INDYCAR's Indianapolis 500, typically pit assignments are made after qualifying, with the fastest qualifiers choosing their pit stall first.
Most North American circuits feature a pit lane with a number of pit stalls and a pit wall that separates the pit lane from the infield, with the garages on a separate road in the infield. In races where there are different series racing together, each series has its own separate garage or are parked in their own area. Circuits in other parts of the world typically have the individual garages open directly onto the pit lane through the team's assigned pit box. In American English, it is common to drop the definite article and just refer to "pit road", whereas in British English one would always refer to "the pit lane". A further difference is that in British English, the term "pit box" is universally used, whereas in American English, one would say "pit stall". In NASCAR, a pit box is a tool, though there is a definitive term used for them.
Purpose
Where it is permitted, refuelling is often an important purpose of a pit stop. Carrying fuel slows down a vehicle, and there is often a limit on the size of the fuel tank, so many races require multiple stops for fuel to complete the race distance in the minimum time. Changing tyres is also common, to permit the use of softer tyres that wear faster but provide more grip, to use tyres suitable for wet conditions, or to use a range of tyres designated by the rules. Teams will aim for each of their vehicles to pit following a planned schedule, with the number of stops determined by many factors, such as fuel capacity, tyre lifespan, and the trade-off between time lost in the pits versus time gained on the track due to the benefits of pit stops. Choosing the optimum pit strategy of how many stops to make and when to make them is crucial in having a successful race. It is also important for teams to take competitors' strategies into account when planning pit stops to avoid being held up behind a competitor where overtaking is difficult or risky. An unscheduled or extended stop, such as for a repair, can be very costly for a driver's chance of success, because while they are stopped for service, competitors remaining on the track are gaining time on them. For this reason, the pit crew often undergo intensive training to perform operations such as tyre changes as quickly as possible, leading to pit stops, for example, as in Formula 1, where the car is only stationary for a few seconds for a regular pit stop.General strategy
In any racing series that permits scheduled pit stops, pit strategy becomes one of the most important features of the race; this is because a race car travelling at 100 miles per hour will travel approximately 150 feet per second. During a ten-second pit stop, a car's competitors will gain approximately one-quarter-mile over the stopped car.However, the car that made the additional pit stop will run faster on the race track than cars that did not make the stop, both because it can carry a smaller amount of fuel, and will also have less wear on its tyres, providing more traction and allowing higher speeds in the corners. In racing series where teams have their choice of different compound tyres, the lower tyre wear may be enough to allow the team to choose to use a tyre with a softer rubber compound that provides increased grip at the expense of faster wear; going longer between stops may even cause enough wear on the softer tyre to cause the tyres to fail.
Because of this, race teams plan a pit strategy prior to the start of every race. This is a schedule for each car's planned pit stops during the race, and takes into account factors such as rate of fuel consumption, weight of fuel, cornering speed with each available tyre compound, rate of tyre wear, the effect of tyre wear on cornering speed, the length of pit road and the track's pit road speed limit, and even expected changes in weather and lighting conditions. The pit strategy does not just include a schedule of when pit stops will happen; it also includes what service and adjustments are scheduled for each pit stop, particularly in endurance racing, where scheduled changes of wear-limited parts such as brake pads may be planned for specific points during the race. The pit strategy is calculated carefully so that the amount of time to be "given away" to other competitors in pit stops is balanced by the time gained while on the track, resulting, in expectation, in the shortest possible time to cover the scheduled distance.
However, a team's pit strategy is not a fixed, immutable thing; it is subject to change during the race to take into account the unpredictable events that happen in every race. In road racing, for example, if the weather changes from dry to rain, teams will be forced to recalculate their pit strategy based on the unscheduled stop to change from dry-weather "slick" tyres to treaded wet-weather tyres. Safety car periods often see mass pit stops by many teams, hoping to take advantage of the slowed pace to reduce the ground lost to other teams while making pit stops; this forces teams that do so to immediately recalculate their pit strategy to optimize it for the remaining race distance after the stop.
Even when a team chooses not to take advantage of the opportunity to stop during a full-course caution, it can still result in significant changes to pit strategy; under caution, the cars run at a reduced speed that results in greatly reduced tyre wear and fuel burn for a distance travelled. Depending on the circumstances, this may be enough for a team to gain more by choosing not to pit, hoping that the reduced fuel burn and tyre wear will allow them to make one pit stop fewer than the other teams, allowing them to gain distance and time on their opponents. At tracks noted for frequent full-course cautions, teams may even plan their entire race strategy around this, using a suspension and aerodynamic setup suited to short sprints instead of extended runs to gain positions in the short bursts of green-flag racing, and planning their pit strategy on the assumption that cautions will extend their fuel mileage and tyre wear enough to make fewer stops than would otherwise be needed to complete the race distance.
Services performed
During a scheduled pit stop, the team's pit crew services the vehicle as quickly as possible, completing a number of different services. The most common services performed are refuelling and changing tyres.Other services performed in routine pit stops include removing debris from radiator air intakes, cleaning the windscreen, and making adjustments to tyre pressure, suspension settings, and aerodynamic devices to optimize the vehicle's performance for the current conditions. In endurance racing, scheduled driver changes and brake pad replacements are also considered "routine" service when done as part of a scheduled pit stop.
An unscheduled pit stop may see other services performed; because unscheduled stops are often due to damage or mechanical problems, they may include emergency repairs and replacement of parts.
In some forms of racing, a team may be ordered to bring a vehicle into the pits as a penalty and either drive through the pit lane at the maximum permitted speed or remain stationary in their pit box for a specified period of time. During this time no services can be performed.
Records
Formula One
In Formula One, mid-race refuelling has been banned since 2010, and cars make pit stops with the primary purpose of changing tyres. Teams sometimes also make adjustments to the front and rear wings and perform minor repairs, most commonly replacing the nose and front wing assembly. A pit stop typically takes approximately 3 seconds to complete. McLaren holds the current world record for the fastest pit stop, with a 1.80-second stop performed at the 2023 Qatar Grand Prix on Lando Norris. Pit strategies generally call for between one and four scheduled stops, depending on the circuit. The drives between pit stops are commonly known as 'stints'.When the car is approximately one lap away from making its stop, the team's pit crew will set up fresh tyres and all needed pit equipment. Because of the overhead pneumatic rig, the team may have all pit mechanics in position before the car's arrival, except for the rear jack man.
Unlike almost all other forms of racing that feature routine pit stops, Formula One rules limit teams to a single pit crew for the mandatory two cars entered. Most other racing series that feature routine pit stops permit each car its own pit stall and crew. Therefore, teams must stagger their pit schedules so that only one of their two cars is in the pits at any given time; otherwise, one car must wait for the other car to finish services. However, with proper timing or in special conditions, it is possible for teams to pit both cars on the same lap without losing significant time; this is known as the 'double stack' strategy. This allows both of the team's drivers to race on equally fresh tyres, preventing either from having an advantage over the other, and helps the team hide the relative performance between two cars to other teams when only one car is in the pits.
One strategy commonly used in Formula One pit stops is the 'undercut' involving two cars battling for track position. In this strategy, the car behind makes an earlier pit stop than the leading car; if successful, the car behind should be able to utilize the advantage of having fresh tyres to reduce the lead of the car they are attempting to overtake. If the gap between the two cars is reduced to less than the time lost in a pit stop, when the leading car pits, the leading car will exit the pits behind the car which pitted first. This strategy is especially effective when the leading car is stuck in traffic and/or if the car behind has clear track to push on, but can be negated if the car behind gets stuck in traffic after their early pit stop or is unable to drive fast enough to neutralize the advantage of the leading car. Similarly, there is the reverse strategy of the 'overcut', where the leading car stays out on their older tyres longer and laps fast enough to maintain or even extend their advantage over the car behind—this strategy may be successful if the leading car's tyres are still in good shape when the car behind pits, sufficiently so that the leading car can push without being overly limited by tyre degradation, or if the car behind gets stuck in traffic, thus negating their ability to utilise their fresher tyres to their advantage.