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.

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 (and thus lower weight) of fuel, and will also have less wear on its tyres, providing more traction and allowing higher speeds in the corners.

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.

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.

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.

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 Formula One, mid-race refuelling has been banned since 2010,[3] and cars make pit stops with the primary purpose of changing tyres.

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.

One strategy commonly used in Formula One pit stops is the 'undercut' involving two cars battling for track position.

As refuelling was a potentially hazardous situation, the mechanics wore fire-resistant multi-layer suits and flame-resistant gloves, long underwear, balaclava, socks and shoes, which had to meet the guidelines set by FIA Standard 8856-2000.

With the exception of repairing damaged tyres, no other mechanic services were allowed to be performed on the cars during the pit stop.

Prior to the 2017–18 season, the rule and scoring system in Formula E allowed for some unusual pit stop strategies.

Notably, this was seen in the 2016 London ePrix, when championship contenders Sébastien Buemi and Lucas di Grassi utilised this strategy after their first lap crash rendered them otherwise unable to score points; Buemi ended up with the fastest lap, winning the Formula E 2016 drivers' championship as a direct result.

For the 2017–18 season, Formula E's rules were amended to restrict the additional point for fastest lap to drivers finishing in the top 10 only, rendering the aforementioned strategy obsolete.

Former NFL player Tim Goad is regarded as the first former professional athlete involved in a pit crew, as a jackman.

Late in a race, a team may only need a small amount of fuel to make it to finish; this is called a "splash and go" and may take as little as 2 to 3 seconds.

Races at short tracks such as Bristol Motor Speedway and Martinsville Speedway are short enough to be completed with only two scheduled stops for fuel, but teams plan on more stops due to rapid tire wear and significant loss of cornering speed on worn tires.

A late caution can force teams to make a tough call: Stay out on worn tires, or pit and give up track position.

The green-white-checker rule can cause headaches, as it can potentially extend the race an unknown number of both green-flag and yellow-flag laps.

A team that qualifies deeper in the field will have a greater opportunity to be stacked behind cars during a pit stop, slowing them down.

As a result, the outside rear changer also serves to wave at the driver to inform him of where his pit box is while holding the air hose up.

IndyCar wheels are affixed to the hubs with a single lug nut, making it easier and faster to change them.

In Super Formula, Japan's top-level single-seater series, a total of six mechanics are allowed to work on a car.

While stops take longer, much more routine maintenance is scheduled during such pit stops, needed to keep the car running for as long as twenty-four hours; this includes major aerodynamic changes to deal with the changing temperature in such a long race, and replacement of certain wear-limited parts, such as brake pads.

Under the rules of the Automobile Club de l'Ouest (ACO) only five mechanics are permitted to work on the car.

One crew member will refuel the car while the other three are responsible for changing tyres and operating the pneumatic jacks.

A fifth crew-member must serve as the team's designated firefighter and must stand ready in the pit stall with a fire extinguisher while the car is being refuelled.

[14] Unlike the ACO, IMSA does not force crews to wait for fuelling to complete before changing tyres, and does not require the car's engine be shut off during the stop.

A routine pit stop with no scheduled maintenance and no driver change generally lasts from thirty to forty seconds.

Should there be significant scheduled maintenance, such as changing brake pads, the stop can easily last well over a minute.