In a few of the most recent cars available, you can change gears simply by pressing a button, turning a knob or toggling a little joystick. Yet at the same time, plenty of different automobiles still require drivers to make use of one foot for the clutch pedal and another for the gas, all while using one hand to control the gear-change lever through a definite design of positions. And many 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-college manual or a modern-day continually variable transmission (CVT), each unit has to do the same work: help transmit the engine’s output to the traveling wheels. It’s a complicated task that we’ll try to make a little simpler today, you start with the fundamentals about why a transmitting is needed to begin with.
Let’s Variable Speed Drive Motor actually start with the normal internal combustion engine. As the fuel-air mix ignites in the cylinders, the pistons begin upgrading and down, and that movement is used 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 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 lower gear means optimum overall performance with the tires moving slower than the engine, while with an increased gear, optimum performance comes with the wheels moving faster.
With a manual transmission, gear shifting is handled by the driver via a gear selector. A lot of today’s vehicles possess five or six forwards gears, but you’ll find older models with anywhere from three to six forward 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. Bigger gears offer plenty of torque but lower speeds, while smaller gears deliver much less torque and invite the car travel more quickly.