In some of the most recent cars in the marketplace, you can change gears simply by pressing a button, turning a knob or toggling a little joystick. Yet simultaneously, plenty of different automobiles still 
require motorists to use one foot for the clutch pedal and another for the gas, all when using one hand to control the gear-change lever through a definite pattern of positions. And many other current vehicles don’t possess any traditional gears at all within their transmissions.
But regardless of whether a vehicle includes a fancy automatic, an old-college manual or a modern-day continuously variable transmitting (CVT), each unit has to do the same work: help transmit the engine’s result to the traveling wheels. It’s a complicated task that we’ll try to make a bit simpler today, starting with the basics about why a transmitting is needed in the first place.
Let’s actually start with the normal internal combustion engine. As the fuel-air combination ignites in the cylinders, the pistons start upgrading and down, and that motion can be used 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 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 lower gear means optimum overall performance with the wheels moving slower compared to the engine, while with a higher gear, optimum performance includes the wheels moving quicker.
With a manual transmission, gear shifting is handled by the driver via a gear selector. A lot of today’s cars have got five or six forwards gears, but you’ll find older models with anywhere from three to six forward gears Variable Speed Drive Motor offered.
A clutch is used to transmit torque from a car’s engine to its manual transmitting. The many gears in a manual transmitting allow the car to travel at different speeds. Bigger gears offer lots of torque but lower speeds, while smaller gears deliver much less torque and invite the car travel more quickly.