This automatic gearbox regulates the gear ratio infinitely variable and, besides, holds the engine speed in the area of the best possible efficiency, highest performance/torque or fewest emissions. It stands in the tradition of the Variomatic, however, has found in the multitronic already a more modern successor.

A steel thrust belt consisting of single steel elements (figure 2) transfers torque from one pulley linked to the crankshaft onto the other which leads to the final drive. The pulleys consist in each case of two parts, thereby having adjustable effective diameters. If both parts are pushed together, the effective diameter of the steel thrust belt becomes bigger and must be reduced at the other pulley accordingly. The transmission ratio can be adapted infinitely variable to the demands. In the animation on top the possible smallest and biggest gear ratio are displayed. A planetary gearbox is necessary for reverse driving (on top between clutch and belt drive). The service elements resemble those of the graded fully automatic system.
As a clutch a torque converter, a magnetic particle clutch or an electronically operated dry clutch or wet clutch are possible. 10/08