Considering the cost savings involved in 
building transmissions with only three moving parts, you’ll understand why car companies have become very interested in CVTs lately.
All of this may sound complicated, nonetheless it isn’t. Theoretically, a CVT is much less complex when compared to a normal automated transmission. A planetary equipment automatic Variable Speed Transmission transmission – sold in the tens of millions this past year – has hundreds of finely machined moving parts. It has wearable friction bands and elaborate electronic and hydraulic settings. A CVT just like the one described above has three basic moving parts: the belt and both pulleys.
There’s another benefit: The cheapest and highest ratios are also further apart than they might be in a conventional step-gear transmission, giving the tranny a greater “ratio spread” This means it is even more flexible.
The engine can always run at the optimum speed for power or for fuel economy, whatever the wheel speed, which means no revving up or down with each gear change, and just the right rpm for the right speed all the time.
As a result, rather than five or six ratios, you get thousands of ratios between the lowest (smallest-diameter pulley environment) and highest (largest-diameter pulley setting).
Here’s an example: When you begin from an end, the control computer de-clamps the insight pulley so the belt turns the tiniest diameter while the output pulley (which goes to the tires) clamps tighter to make the belt change its largest diameter. This produces the cheapest gear ratio (say, 3.0-to-1) for the quickest acceleration. As acceleration builds, the pc varies the pulley diameters, as conditions dictate, to find the best balance of fuel economic climate and power.
