Hyundai unveils Continuously Variable Valve Duration tech

Hyundai has unveiled an engine technology that can control the timing of the valve opening and closing depending on driving conditions. It is called Continuously Variable Valve Duration (CVVD) and it will be offered in future Hyundai and Kia models. According to Hyundai, CVVD increases engine performance by 4% and fuel efficiency by 5%. It is also claimed to reduce emissions by 12%.

Technologies like Continuously Variable Valve Timing (CVVT) and Continuously Variable Valve Lift (CVVL) have been around for some time. CVVT manages the timing of the valve's opening and closing, while the latter adjusts the depth of the opening. Hyundai's CVVD, on the other hand, regulates the duration for which the valve is opened depending on the driving condition.

When cruising at a constant speed, CVVD opens the intake valve from the middle to end of the compression stroke. This is claimed to improve fuel efficiency by reducing the resistance caused by compression. When engine output is high, the intake valve is closed at the beginning of the compression stroke to maximize the amount of air used for the explosion. This is claimed to improve torque and therefore acceleration.

CVVD will debut on the Smartstream G1.6 T-GDi engine. It is a V4 turbocharged petrol engine that produces 178 BHP and 265 Nm of torque. The engine features Low-Pressure Exhaust Gas Recirculation (LP EGR) that is claimed to increase efficiency under high load conditions and Integrated Thermal Management System that is said to reduce engine friction by 34%. The new engine will debut on the Hyundai Sonata Turbo later this year.