Heel-and-toe shifting is a driving technique used mostly in performance driving, although some drivers use it on the road in everyday conditions in the interest of effectiveness. It involves operating the throttle and brake pedals simultaneously with the right foot, while facilitating normal activation of the clutch with the left foot. It is used when braking and downshifting simultaneously (prior to entering a turn), and allows the driver to "blip" the throttle to raise the engine speed and smoothly engage the lower gear. (See Synchronized transmission.)
Heel-and-toe shifting and heel-and-toe-double-clutching (described below) is used before entry into a turn while a vehicle is under braking, preparing the transmission to be in the optimal range of rpm to accelerate out of the turn. One benefit of downshifting before entering a turn is to eliminate the jolt to the drivetrain, or any other unwanted dynamics. The jolt will not upset the vehicle as badly when going in a straight line, but the same jolt while turning may upset the vehicle enough to cause loss of control if it occurs after the turn has begun. Sporting vehicles are usually modified (if necessary) so that the heights of the brake and accelerator pedals are closely matched when the brake is sufficiently depressed, and the pedals are not too far apart to permit easy use of heel-and-toe.
The name, stemming from earlier automotive designs where the accelerator pedal was on the left and could be actuated with the heel while the brake pedal was actuated with the toe, is misleading regarding how the technique is carried out in modern cars, i.e., operating the brake with the left edge of the foot, while rocking it down and to the right to operate the throttle. With practice, it becomes possible to smoothly and independently operate both pedals with one foot. The technique is common in all forms of motorsport, especially rallying.
As the power band of most rally cars is high in the rev range, this technique can also be used to ensure that engine rpm does not drop below the power band of the car while under braking. If this happened there would be a delay between the driver accelerating after the corner and when the car responds; this is especially true in turbocharged cars. This technique ensures that maximum power can be reached the instant the brake pedal is released and the accelerator fully depressed.
Heel-and-toe-double-clutch is the technique of downshifting more than one gear to use engine braking in the intermediate gear. This provides maximum braking and optimal engine RPM for exiting the corner. While this is not double-clutching in the traditional sense, the term is used to describe this technique since the clutch is pressed more than once.
An unrelated technique called left-foot braking should not be confused with heel-and-toe.
- Speed Secrets: Professional Race Driving Techniques by Ross Bentley - ISBN 0-7603-0518-8
- Secrets of Solo Racing: Expert Techniques for Autocrossing and Time Trials by Henry A. Watts - ISBN 0-9620573-1-2