Abstract: The invention concerns a system for evaluating vehicle, drive and operation parameters of a vehicle to select and adjust by means of a microprocessor a speed ratio of a gear according to predetermined calculation rules, characteristic values and characteristic fields wherein an acceleration of the vehicle is mathematically calculated from a number of revolutions of a drive train comprising engine and gear, the number of revolutions corresponding to the driving speed. The problem is to provide for different gear types a uniform system which requires only a few parameters adapted to the vehicle for selecting speed ratio and gear shift. This is attained by the fact that a minimum dwelling time (&Dgr;tf) is associated to each speed ratio range. To each change of speed ratio (ig) is further associated an adjustment time (&Dgr;tz) which in the average is required for the gear to complete a speed ratio change (&Dgr;ig).

Abstract: A coupling disk is used in an engine with an output element rotatable about an axis and a drive train having an input element rotatable generally about the same axis. The disk has an inner ring of bores by means of which it is bolted to the output element an outer ring of bores by means of which it is bolted to the input element. The disk is formed with a plurality of radially outwardly projecting tabs separated by radially outwardly open cutouts and each formed with a respective one of the outer bores. The cutouts extend radially inward past regions of contact between the tabs and the input element and the tabs are each formed with generally tangentially extending corrugations.