Toyota's new engine valve mechanism
Valvematic: VVT-i + variable valve lift

MT,
18 June 2007.

With its newly developed variable valve lift mechanism, Toyota goes a step further in the evolution of its Variable Valve Timing-intelligent (VVT-i ) system.

Called Valvematic, the new variable valve lift mechanism combines the advantages of the VVT-i technology (it controls the timing of intake valve opening/closing) with a new mechanism that can also control the intake valve lift volume.

In other words, VVT-i controls the timing (duration of the opening) while the new mechanism will also control the distance of the opening (lift).

Conventional engines control air intake (outside air is filtered then directed to the combustion chambers, naturally or compressed by a direct compressor or a turbocompressor) using a throttle valve. With Valvematic, the volume of air taken in is adjusted by continuously controlling the intake valve lift volume and timing of valve opening and closing, bringing optimal performance based on the engine’s operational condition, combining high fuel efficiency with dynamic performance.

The first application of Valvematic will arrive in a new 2.0-litre engine to be introduced soon. This new system further evolves the Toyota petrol engine and improves fuel efficiency by between 5 and 10 per cent (depending on driving conditions), reduces CO₂ emissions, boosts power output by at least 10 per cent and enhances throttle response.

As a part of its efforts to reduce CO₂ emissions through high fuel efficiency and to achieve cleaner exhaust emissions, Toyota Motor Corporation (TMC) plans to completely revamp its petrol engine and transmission lineup by 2010.