First used as a necessary technique for pre-WWII clunky gear mechanisms, heel-toe shifting is largely unnecessary for daily drivers. Used mostly by motorsports professionals in high-octane cars and motorcycles, it’s not really something you need to learn unless, of course, you want to feel like a professional motorsports driver when you take the family van to the store to get milk. In which case, you should absolutely learn how to do it.
The fancy footwork of heel-toe shifting does have a lot of benefits. It reduces stress on the transmission, keeps the weight of your vehicle balanced during gear changes, helps to prevent wheel lock, and allows smoother and more efficient acceleration around corners.
At its core, heel-toe shifting is a way of getting around the fact that we don’t have three legs. Utilized mostly when approaching corners, it’s used to match engine speed (RPMs) to road speed through gear changes.
When you approach a corner and apply the brake, your car slows down and engine speed drops. Coming out of the corner, to compensate for your reduced speed, you shift into a lower gear, but depressing the clutch only causes engine speed to drop faster. By the time you’re ready to release the clutch in 2nd gear, the engine is practically idling even though you’re still rolling along at a good clip. When you do release the clutch, the engine has to race to catch up with the rest of the car.
These big swings in engine speed vs. road speed are highly inefficient and make all the difference in high-end racing where smooth acceleration around a corner is critical. Heel-toe shifting maintains engine speed so that it stays constant with your road speed, maximizing efficiency and power. To accomplish this, your brake foot rotates so that you can operate the throttle and the brake simultaneously during gear changes. Sound complicated? Follow the guide above, do some practicing, and you’ll have it down in no time.
(via The Art of Manliness)