Semi-Automatic Transmission (SAT) / Paddle Shifters

A semi-automatic transmission (SAT) (also known as a clutchless manual transmission, automated manual transmission, flappy-paddle gearbox, or paddle-shift gearbox) is an automobile transmission that does not change gears automatically, but rather facilitates manual gear changes by dispensing with the need to press a clutch pedal at the same time as changing gears. View more details after the cut…

It uses electronic sensors, pneumatics, processors and actuators to execute gear shifts on input from the driver or by a computer. This removes the need for a clutch pedal which the driver otherwise needs to depress before making a gear change, since the clutch itself is actuated by electronic equipment which can synchronise the timing and torque required to make quick, smooth gear shifts. The system was designed by automobile manufacturers to provide a better driving experience through fast overtaking maneuvers on highways.

Basically, you need to shift up when you start to feel the smart car straining to accelerate. The smart electronic display on your dash will also give you a visual indicator arrow telling you when to shift, but consider that a guideline or suggestion, as it's not always 100% accurate.

You should shift down as your speed drops. However, the great thing about a smart car, even in pure manual mode, is that it automatically will shift down to a lower gear as you slow down. If you don't want to wait for that to happen, though, you can use the paddles (or stick).