Formula 1 for dummies: the DRS
The Drag Reduction System, or DRS for short, is a device available to Formula 1 drivers when they're trying to overtake a rival during a race. It was first introduced back in 2011, and the main idea behind the concept has remained the same ever since: by adjusting the rear wing from behind the wheel, a driver can gain extra speed in a straight line to help them get closer to the car ahead and launch an overtake.
In the race, DRS is available when a driver is within one second of the car ahead, and only in specific areas of the track designated as DRS zones – usually on long straights or full-throttle sections. It can also be used freely in those same zones in practice and qualifying sessions, regardless of whether you're following another car or not.
The gap between cars is measured in a dedicated place on the track before DRS zones, known as the detection point. Sometimes, a single detection point might be used to determine DRS availability for multiple zones – for example if those zones are located close to each other.
If a driver is measured as being within one second of the car ahead in that detection zone, the DRS will become available to them at the subsequent activation point(s). They will usually be notified by a light on their steering wheel, or by a beep in their ears. To use DRS at this point, the driver presses a button on their steering wheel that opens a flap in the rear wing.
While a rear wing is designed to create downforce that allows for greater speed through corners, in a straight line its large surface produces aerodynamic drag which restricts speed. Opening the DRS flap reduces this drag, allowing for faster acceleration and greater top speed. This can help a following car to close on the one in front – which will only have DRS available to defend if it's also within one second of another car ahead. When multiple consecutive cars have DRS available, you can get what's known as a ‘DRS train' where the usual advantage is negated and gaps can remain consistent for many laps.
The DRS flap will be closed again if the driver lifts off the accelerator or presses the brake pedal. They can also switch it off by pressing the button for a second time: they may wish to do this to avoid creating instability by braking before the downforce has fully reattached.
There are a few occasions where DRS will not be made available even when two cars are running closely enough. One such point is in the two laps after a race start, or after a restart. Race control can also disable DRS whenever they feel it is necessary for safety reasons, such as when the track is wet or when there has been a yellow-flag incident or there is debris on the circuit.