In a few of the latest cars available, you can shift gears simply by pressing a button, turning a knob or toggling a small joystick. Yet simultaneously, plenty of different vehicles still require Variable Speed Transmission motorists to use one foot for the clutch pedal and another for the gas, all when using one hand to manipulate the gear-shift lever through a distinct pattern of positions. And many other current vehicles don’t possess any traditional gears at all in their transmissions.
But whether or not a vehicle has a fancy automatic, an old-college manual or a modern-day consistently variable transmitting (CVT), each unit has to do the same job: 
help transmit the engine’s output to the generating wheels. It’s a complicated task that we’ll try to make a bit simpler today, starting with the fundamentals about why a transmission is needed in the first place.
Let’s actually start with the typical internal combustion engine. As the fuel-air mixture ignites in the cylinders, the pistons start moving up 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 off in the cylinders and the complete process moves faster 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 wheels 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 with a gear selector. A lot of today’s cars possess five or six forwards gears, but you’ll discover older models with anywhere from three to six forward gears offered.
A clutch is utilized to transmit torque from a car’s engine to its manual transmission. The various gears in a manual transmission allow the car to travel at different speeds. Larger gears offer plenty of torque but lower speeds, while smaller sized gears deliver much less torque and invite the car travel more quickly.