In a few of the newest cars in the marketplace, you can change gears by simply pressing a button, turning a knob or toggling a little joystick. Yet at the same time, plenty of different automobiles still require motorists 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 Variable Speed Transmission definite design of positions. And many other current cars don’t have 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 constantly variable transmitting (CVT), each unit must do the same work: help transmit the engine’s result to the generating wheels. It’s a complicated task that we’ll try to make a little simpler today, starting with the fundamentals about why a tranny is needed to begin with.
Let’s actually start with the normal internal combustion engine. As the fuel-air blend 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 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 lower gear means optimum functionality with the wheels moving slower compared to 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 cars possess five or six ahead gears, but you’ll find older models with from three to six forward gears offered.
A clutch is used to transmit torque from a car’s engine to its manual transmitting. The many gears in a manual transmission allow the car to travel at different speeds. Bigger gears offer plenty of torque but lower speeds, while smaller sized gears deliver less torque and invite the car travel more quickly.