Hyundai's new CVVD engine ups power and efficiency, reduces emissions

By CARSIFU | 5 July 2019

SEOUL: Hyundai Motor Group has developed the world’s first Continuously Variable Valve Duration (CVVD) technology that optimises engine performance and fuel efficiency while reducing emissions.

The South Korean carmaker will feature its new technology in upcoming Hyundai and Kia vehicles

The tech was revealed at Hyundai Motorstudio Goyang alongside the Smartstream G1.6 T-GDi - the first engine to feature it.

The valve control technology regulates the duration of valve opening and closing according to driving conditions, achieving a 4% boost in performance, 5% improvement in fuel efficiency and a 12% reduction in emissions.

Until now, an internal combustion engine’s performance and efficiency have been governed by variable valve control technology that adjusts the timing of the valves' opening and closing as well as depth-of-opening.

With engine power produced through its four-stroke cycle of air and fuel intake-compression-combustion-exhaust.

Now, CVVD can adjust how long a valve is opened.

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 and helps improve fuel efficiency by reducing the resistance caused by compression.

On the other hand, when engine output is high - when the car is being driven at a high speed, the intake valve is closed at the beginning of the compression stroke to maximize the amount of air used for combustion, thereby enhancing torque for better acceleration.

Unveiled alongside the new CVVD technology is the new Smartstream G1.6 T-GDi Engine, a turbocharged petrol engine that produces 180hp and 265Nm of torque.

Hyundai CVVD Engine Technology - 02

The new powertrain is the first to utilize the company's new technology and also features Low-Pressure Exhaust Gas Recirculation (LP EGR) to further optimise fuel efficiency.

The exhaust gas recirculation system returns some of the gas burnt by the engine to the combustion chamber, producing a cooling effect and reducing the emission of nitrogen oxides.

The G1.6 T-GDi also features a low-pressure system that redirects the burnt emission gas to the front of the turbocharger compressor, rather than the intake system, to increase efficiency under high load conditions.

Additionally, the new unit has an Integrated Thermal Management System that quickly heats or cools the engine to an optimal temperature, and a strong direct spray system that achieves 350bar, surpassing the 250bar of the previous T-GDi engine.

Additionally, engine friction is reduced by 34% with the application of low friction moving parts.

The new Smartstream G1.6 T-GDi engine will be applied in the Hyundai Sonata Turbo, which is set for introduction in the second half of this year.

The Sonata turbo's premiere will mark the first in a series of new Hyundai and Kia vehicles featuring the engine.