Called Valvematic, the new Toyota system combines VVT-i (Variable Valve Timing-intelligent), which continuously controls the intake valve opening and closing timing, with a new mechanism that continuously controls the intake valve lift to control the volume of intake air to the cylinder.
While conventional engines rely on a throttle-valve to control the volume of intake air to the cylinders, Valvematic continually adjusts the volume of air drawn into the cylinders by controlling the amount of lift for the valve together with the timing of the valve opening and closing.
This ensures optimal performance based on the engine?s operating condition at any given time. Improved fuel efficiency and dynamic performance are advantages of the system.
A new 2.0 litre engine developed by Toyota with the Valvematic system shows an improvement of between 5% and 10% in fuel consumption (depending on driving conditions) over a conventional 2.0 litre engine fitted with a regular throttle mechanism. CO2 emissions are reduced and power output is boosted by 10% together with improved acceleration response.
According to Toyota Valvematic technology will be introduced in production shortly fitted to a new model (probably the Auris/Corolla range) featuring a 2.0 litre engine.