In some of the latest cars on the market, 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 drivers to make use of 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 design of positions. And many other current vehicles don’t have any traditional gears at all in their transmissions.
But whether or not a vehicle has a fancy automatic, an old-school manual or a modern-day continually variable tranny (CVT), each unit has to do the same job: help transmit the engine’s result to the traveling wheels. It’s a complex task that we’ll try to make a bit simpler today, you start with the fundamentals about why a transmission is needed to begin with.
Let’s actually start with the normal internal combustion engine. As the fuel-air mixture ignites in the cylinders, the pistons begin upgrading and down, and that motion is 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 Variable Speed Drive Motor optimum functionality with the wheels 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 with a gear selector. Many of today’s vehicles have got five or six forwards gears, but you’ll find older models with 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 lots of torque but lower speeds, while smaller sized gears deliver less torque and invite the car travel quicker.