Left-foot braking

Left-foot braking is the technique of using the left foot to operate the brake pedal in an automobile, leaving the right foot dedicated to the throttle pedal. It contrasts with the practice of using the left foot to operate the clutch pedal, leaving the right foot to share the duties of controlling both brake and accelerator pedals.

At its most basic purpose, left-foot braking can be used to decrease the time spent moving the right foot between the brake and throttle pedals, and can also be used to control load transfer.

It is most commonly used in auto racing (simultaneous gas and brake keeps turbo pressure and reduces turbo lag), but is also used by some drivers for use with an automatic transmission or in some electric cars, as the left foot is not needed to operate a clutch pedal.

Karts, many open wheelers, and some modern road cars (cars that are mounted with automatic transmission or semi-automatic transmission as used in motorsports such as Formula One), have no foot-operated clutch, and so allow the driver to use their left foot to brake.

One common race situation that requires left-foot braking is when a racer is cornering under power. If the driver does not want to lift off the throttle, potentially causing trailing-throttle oversteer, left-foot braking can induce a mild oversteer situation, and help the car "tuck", or turn-in better. Mild left-foot braking can also help reduce understeer.

In rallying left-foot braking is very beneficial, especially to front-wheel drive vehicles. It is closely related to the handbrake turn, but involves locking the rear wheels using the foot brake (retarding actually, to reduce traction, rarely fully locking - best considered a misapplication), which is set up to apply a significant pressure bias to the rear brakes. The vehicle is balanced using engine power by use of the accelerator pedal, operated by the right foot. The left foot is thus brought into play to operate the brake. It is not as necessary to use this technique with rear-wheel drive and four-wheel drive rally vehicles because they can be easily turned rapidly by using excess power to the wheels and the use of opposite lock steering, however the technique is still beneficial when the driver needs to decelerate and slide at the same time. In rear wheel drive, left foot braking can be used when the car is at opposite lock and about to spin. Using throttle and brake will lock the front tires but not the rears, thus giving the rears more traction and bringing the front end around.

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Wikipedia