An apu doesn't generate nearly enough power to taxi the aircraft. Since a large APU is essentially another turbine, you're back to using a turbine to propel the

An apu doesn't generate nearly enough power to taxi the aircraft. Since a large APU is essentially another turbine, you're back to using a turbine to propel the aircraft. If this really were a place to save money then the simplest solution would just have the tug pull it all the way to the runway. That way the aircraft doesn't need to take on additional weight for motors/apus which will sap fuel economy during flight.