In the Lancer CVT transmision there are to simplify things a
series of "belts" that allow the transmision to vary the gear ratio
based on the vehicle's needs. For example, if the driver
accelerates quickly it will switch through the gears and keep RPMs
high as you accelerate to maximum speed; conversely if the driver
accelerates slowly it will maintain low end torque to and keep RPM
in the medium range to maximize fuel economy.