In some of the most recent cars available, you can shift gears by simply pressing a button, turning a knob or toggling a small joystick. Yet simultaneously, plenty of different automobiles still require motorists to use one foot for the clutch pedal and another for the gas, all while using one hand to control the gear-change lever through a distinct pattern of positions. And several other current vehicles don’t have any traditional gears at all in their transmissions.

But regardless of whether a vehicle has a fancy automatic, an old-school manual or a modern-day Variable Speed Drive Motor continuously variable transmission (CVT), each unit must do the same job: help transmit the engine’s output to the driving wheels. It’s a complicated task that we’ll make an effort to make a bit simpler today, starting with the fundamentals about why a transmitting is needed to begin with.
Let’s actually start with the typical internal combustion engine. As the fuel-air blend ignites in the cylinders, the pistons start upgrading and down, and that movement is utilized to spin the car’s crankshaft. When the driver presses on the gas pedal, there’s more fuel to burn in the cylinders and the complete process moves quicker and faster.

What the transmission does is change the ratio between how fast the engine is spinning and how fast the driving wheels are moving. A lesser gear means optimum efficiency with the tires moving slower than the engine, while with a higher gear, optimum performance comes with the wheels moving faster.
With a manual transmission, gear shifting is handled by the driver via a gear selector. Many of today’s vehicles possess five or six ahead gears, but you’ll find older models with from three to six ahead gears offered.

A clutch is used to transmit torque from a car’s engine to its manual tranny. The various gears in a manual tranny allow the car to visit at different speeds. Larger gears offer lots of torque but lower speeds, while smaller gears deliver less torque and allow the car travel more quickly.