All-new CVVD tech revealed by Hyundai Motors

KUALA LUMPUR: Hyundai Motor Group has revealed the new Continuously Variable Valve Duration, a.k.a., CVVD tech. This new tech will be tuned in the Smartstream G 1.6-litre four-cylinder turbo T-GDi mill, powering the all-new Hyundai Sonata. In the future, more Hyundai and Kia cars will benefit from this engine technology; details will be released later on by the automaker.

As per Hyundai, the CVVD tech regulates the valve opening and closing duration concerning the driving conditions. This allows for 12% less emissions, 4% increase in performance, and 5% improvement in fuel efficiency.

In a conventional four-stroke internal combustion unit, the timing of the closing and opening of the valve is adjusted by the variable valve control system or via controlling the volume of the air entering by adjusting the depth of the opening. Both exercises are similar to what happens in Continuously Variable Valve Timing and Continuously Variable Valve Lift setup, respectively.

However, in both these setups, the valve duration can not be regulated as the opening timing controls the closing timing, thus making it unresponsive to the change in driving condition. This is not the issue with Hyundai's new CVVD as it adjusts how long a valve remains open.

Take for example, when the car is being driven at a constant speed and only needs limited engine power, the CVVD open the intake valve from the middle to end. This would call for improved fuel efficiency by lowering the resistance due to compression. On the contrary, when higher engine power is needed, the valve would close at the beginning, thus maximising the amount of air used for combustion and improve torque output.

Coming to the Smartstream G 1.6-litre engine, the mill churns out a maximum power of 180 hp along with a peak torque of 264 Nm. This unit is not equipped with the CVVD but also gets a Low-Pressure Exhaust Gas Recirculation (LP EGR).