MultiDrive varies the transmission’s gear ratio continuously. This means that it can be described as an automatic transmission with an infinite number of ratios allowing for the flexibility at any time that the most suitable ratio to be chosen whilst optimising both performance and fuel efficiency.
How does it work?
A CVT transmission uses a pair of variable-diameter pulleys, each shaped like a cone. Running between these ‘cones’ is a metal belt which conveys the power from one cone to the other. One cone is connected to the engine (input shaft), the other to the drive wheels (output shaft).
Each of the cones are moveable. As they come closer together or further apart the position of the belt is forced to ride higher or lower on the cone, varying the transmission’s ratio (the number of times the output shaft revolves for each revolution of the engine). Having the belt ride on the narrowest end of the input cone and the widest part of the output cone gives a low gear ratio. (A large number of engine revolutions producing a small number of output revolutions, better for low speed acceleration.)
As the car accelerates, the position of the belt on the cones varies. This occurs in a similar fashion to the way a conventional automatic or manual transmission works, but while conventional transmissions change the ratio in stages by shifting gears, the CVT continuously varies the ratio.
MultiDrive features a manual shift mode that can be controlled either from the gear shift lever or paddles mounted on the rear of the steering wheel. 7 gears of pre-determined ratio positions are available to the driver for the manual mode. There are seven ratios providing a seamless, stepless gear change.