Moreover, to increase maximum thermal efficiency, Toyota Industries employed an intake port having a shape that makes it easy to let air in and a common-rail fuel injection system with an improved injection pressure and optimized the shape of the combustion chamber.
As a turbo supercharger, a variable-geometry turbocharger was employed. It is equipped with a variable nozzle vane. When there is a sudden need for a high torque in a low-speed, low-load state (e.g. when the vehicle starts moving after waiting at a traffic signal), the vane is closed and exhaust gas is received by the turbine wheel.
As a result, revolution speed is increased to rapidly increase supercharging pressure. And a large amount of air is sent to the engine, realizing a high torque.
Toyota Industries improved the efficiency of the variable-geometry turbocharger while reducing its size by about 30%. With the increased efficiency, the response to gas pedal operation was improved by about 50%. The company also changed the shapes of the turbine wheel's and impeller's blades and replaced a full-float sliding bearing with a semi-float sliding type.