Hystat transmission having pressure override control

A transmission for use with a machine is disclosed. The transmission may have a pump, a motor fluidly connected to receive pressurized fluid from the pump and propel the machine, and an operator input device configured to generate a signal indicative of an operator desired gear ratio of the transmission. The transmission may also have a controller in communication with the pump, the motor, and the operator input device. The controller may be configured to determine an desired gear ratio of the transmission as a function of the signal, and determine an efficiency loss of the transmission at the desired gear ratio. The controller may also be configured to select a known setting of at least one of the pump and motor that provides the desired gear ratio and accounts for the efficiency loss.