In motor racing, the drag reduction system (DRS) is a form of driver-adjustable bodywork aimed at reducing aerodynamic drag in order to increase top speed and promote overtaking. It is an adjustable rear wing of the car, which moves in response to driver commands.[1] DRS often comes with conditions, such as the requirement in Formula 1 that the pursuing car must be within one second (when both cars cross the detection point) for DRS to be activated.
DRS was introduced in Formula One in 2011. The use of DRS is an exception to the rule banning any moving parts whose primary purpose is to affect the aerodynamics of the car. The system is also used in the Formula Renault 3.5 since 2012,[2] Deutsche Tourenwagen Masters since 2013,[3] Super Formula since 2014, GP2 Series later FIA Formula 2 Championship since 2015, GP3 Series later FIA Formula 3 Championship since 2017. An adjustable wing was also used by the Nissan DeltaWing at the 2012 24 Hours of Le Mans, although with free usage.
In Formula One, the DRS opens an adjustable flap on the rear wing of the car, in order to reduce drag, thus giving a pursuing car an overtaking advantage over the car in front. The FIA estimate the speed increase to be between 10–12 km/h (6.2–7.5 mph) by the end of the activation zone,[4] while others, such as technical staff at racecar-engineering.com,[5] cite a much lower figure of 4–5 km/h (2.5–3.1 mph). When the DRS is deactivated or closed, it increases downforce, giving better cornering.
Between 2011 and 2023, the device could only be used during a race after two racing laps had been completed, and when the pursuing car entered a designated "activation" zone defined by the FIA. This also included having to wait 2 laps after a safety car restart. In 2024 the rule was changed and now the device can be used during a race after only one racing lap after the race start or a safety car restart has been completed.[6]
In 2011, the FIA increased the number of DRS zones to two on some circuits featuring multiple long straights. In Valencia and in Montreal, two zones were endorsed on consecutive long straights, while in Monza and in Buddh, two zones were created on separate parts of the circuit. Two zones had originally been planned for every race with multiple long straights from Montreal onwards (depending on Montreal/Valencia success), but this was not implemented.[7] However, at the penultimate round of the 2011 season, two zones on consecutive long straights saw a return at Yas Marina.
When usage of the DRS remained legal for the 2012 season, a second zone was added to the opening round's track in Melbourne. A third DRS zone was added during 2018 and 2019 seasons in Australia, Bahrain, Canada, Austria, Singapore, and Mexico. In the 2022 season, a fourth zone was initially added for the track in Melbourne, after the circuit redevelopment, before being removed for safety reasons.[8][9] In the 2023 season the zone was re-added.[10] Bahrain, Jeddah, Melbourne, Baku and Miami had their DRS zones adjusted based on whether the FIA deemed DRS made overtaking at these five circuits too easy or too hard in 2022.[11]
The horizontal elements of the rear wing consist of the main plane and the flap. The DRS allows the flap to lift a maximum of 85 millimetres (3.3 in) from the fixed main plane. This reduces opposition (drag) to airflow against the wing and results in less downforce. In the absence of significant lateral forces (straight line), less downforce allows faster acceleration and potential top speed, unless limited by the top gear ratio and engine rev limiter. Sam Michael, sporting director of the McLaren team, believes that DRS in qualifying will be worth about half a second per lap.
The effectiveness of the DRS will vary from track to track and, to a lesser extent, from car to car. The system's effectiveness was reviewed in 2011 to see if overtaking could be made easier, but not to the extent that driver skill is sidelined. The effectiveness of DRS seems likely to be determined by the level of downforce at a given circuit (where the cars are in low drag trim at circuits like Monza, the effects may be smaller), length of the activation zone, and characteristics of the track immediately after the DRS zone.
Use of DRS is restricted by the F1 rules; it is permitted only when both:
Further:
A dashboard light notifies the driver when the system is enabled (the driver can also see the system deploy in his wing mirrors). The system is deactivated when the driver releases the button or uses the brakes.
There are lines on the track to show the area where the one-second proximity is being detected (the detection point) and a line later on the track (the activation point), along with a sign vertically marked "DRS" where the DRS zone itself begins.
There has been a mixed reaction to the introduction of DRS in Formula One amongst both fans and drivers. Some believe that this is the solution to the lack of overtaking in F1 in recent years while others believe this has made overtaking too easy.[12] Former Formula One and Team Penske IndyCar Series driver Juan Pablo Montoya described it as "like giving Picasso Photoshop".[13] The principal argument for the opponents of DRS is that the driver in front does not have an equal chance of defending his position because they are not allowed to deploy DRS to defend. The tightening up on the rules for a leading driver defending their position has added to this controversy.[14] In 2018, then-Scuderia Ferrari driver Sebastian Vettel stated that he preferred throwing bananas Mario Kart-style over the use of DRS,[15] arguing that it's "artificial".[16]
The McLaren P1 coupé is the first road car to have incorporated the F1-style rear wing Drag Reduction Systems.[17] McLaren Senna GTR and Porsche 911 (992) GT3 RS later followed suit by the introduction of the same system in 2019 and 2022 respectively.[18]
