Hyundai Announces World’s First Continuously Variable Valve Duration Engine

Hyundai Motor Group has unveiled the world's first Continuously Variable Valve Duration (CVVD) technology to feature in an engine. The South Korean car company revealed the CVVD on Wednesday, July 3, at Hyundai Motorstudio Goyang, featuring in its new Smartstream G1.6 T-GDi engine. The technology, along with the engine, is set to appear in future Hyundai and Kia vehicles.

The way CVVD works is that it manages the length of time that the valves open and close depending on driving conditions, thereby boosting performance and optimizing fuel efficiency for a reliable yet eco-friendly engine. With CVVD, Hyundai's engine delivers four-percent enhanced performance, 5-percent improvement in fuel economy, and a 12-percent reduction in emissions.

"The development of the CVVD technology is a good example how Hyundai Motor Group is strengthening our powertrain technology," said Albert Biermann, President and Head of Research and Development Division at Hyundai Motor Group. "We will continue our innovation efforts to bring forth paradigm shifts and ensure sustainability of our business model."

Until CVVD, variable valve control could not regulate valve duration, and thus, cannot respond to different driving conditions. CVVD improves on the technology by adjusting how long the valve remains open.

When the vehicle is cruising and requires low engine output, CVVD leaves the intake valve open until the middle of the compression stroke then closes it at the stroke's end, thus reducing the resistance caused by compression. This, in turn, improves fuel efficiency.

Contrarily, when the car is at high speeds, the intake valve closes to allow more air into the combustion chamber and push the torque to improve acceleration.

This technology is present in the new Smartstream G1.6 T-GDi engine, an inline-four gasoline turbo unit with 180 hp and 265 Nm. Aside from CVVD, the new engine also features a Low-Pressure Exhaust Gas Recirculation (LP EGR), which returns some of the emissions back into the combustion chamber to produce a cooling effect and reduce the emission of nitrogen oxides. Some of the emission gas goes to the front of the turbocharger compressor to increase efficiency under high-load condition. Additionally, an Integrated Thermal Management System quickly heats or cools the engine to an optimal temperature while reducing engine friction by 34 percent, thanks to the implementation of low-friction moving parts.

The new Smartstream G1.6 T-GDi will appear in the upcoming Hyundai Sonata Turbo, set for release at the second half of this year. This release will mark the first in a series of new Hyundai and Kia vehicles equipped with the engine.