Transmission gear ratio selection controlling method for vehicle, involves maintaining gear ratio if quantity representing power to be supplied to increased engine speed is lower than threshold or else increasing gear ratio

摘要

The method involves decreasing gear ratio if a quantity representing power to be supplied by a drive train to a current engine speed is lower than a threshold. The gear ratio is maintained at constant value if a quantity representing power to be supplied by the train to increased engine speed is lower than another threshold or else the gear ratio is increased. The former threshold is lower than the latter threshold. An Independent claim is also included for a vehicle equipped with automatic transmission gear ratio.