The Hyundai Motor Group is pushing its engine technology to a new direction with the announcement of the world’s first Continuously Variable Valve Duration (CVVD) technology which will go into both future Hyundai and Kia vehicles starting with the Sonata’s 1.6-liter Smartstream G engine.

Before CVVD, an engine’s performance and efficiency is governed by variable valve control tech that adjusts the timing of valve opening and closing, and the depth of the valve’s opening. Hyundai takes a new direction by actually adjusting how long a valve stays open with CVVD.

When the vehicle is maintaining a constant speed and requires low engine output, CVVD opens the intake valve from the middle to end of the compression stroke. This helps to improve fuel efficiency by reducing the resistance caused by compression. On the other hand, when engine output is high, such as when the car is driving at a high speed, the intake valve is closed at the beginning of the compression stroke to maximize the amount of air used for the explosion, enhancing torque to improve acceleration.


All in all, Hyundai says that CVVD should achieve a further 4 percent boost in performance and 5 percent improvement in fuel efficiency. Furthermore, it cuts emissions by an impressive 12 percent.

The new CVVD technology will debut first in the group’s Smartstream G1.6 T-GDi engine. This 4-cylinder turbocharged gasoline engine makes 180 horsepower and 265 Nm of torque.

Other key features of this new engine include a Low-Pressure Exhaust Gas Recirculation (LP EGR) system that re-directs burnt emission gas to the front of the turbocharger, rather than the intake system, to increase efficiency under high loads. It also has a stronger direct fuel spray system that achieves 350bar compared to the current 250bar. Engine friction is also reduced by 34 percent.

The Smartstream G1.6 T-GDi will debut in the second half of 2019 and will mark the first in a series of new Hyundai and Kia vehicles that feature the engine.