In a few of the latest 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 drivers to use one foot for the clutch pedal and another for the gas, all while using one hand to manipulate the gear-change lever through a distinct pattern of positions. And several other current cars don’t possess any traditional gears at all within their transmissions.
But whether or not a vehicle includes a fancy 
automatic, an old-college manual or a modern-day consistently variable transmission (CVT), each unit must do the same job: help transmit the engine’s output to the generating wheels. It’s a complex task that we’ll try to make a little simpler today, starting with the fundamentals about why a transmission is needed to begin with.
Let’s actually begin with the typical internal combustion engine. As the fuel-air mixture ignites in the cylinders, the pistons start moving up and down, and that motion is utilized 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 quicker and faster.
What the transmission does is change the ratio between how fast the engine is Variable Speed Transmission spinning and how fast the driving wheels are moving. A lesser gear means optimum overall performance with the wheels moving slower compared to the engine, while with an increased gear, optimum performance includes the wheels moving faster.
With a manual transmission, gear shifting is handled by the driver via a gear selector. Many of today’s cars possess five or six forward gears, but you’ll discover older models with anywhere from three to six forwards gears offered.
A clutch can be 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 gears deliver much less torque and invite the car travel quicker.