New petrol engine claims to be 5 per cent more efficient while bringing a 4 per cent boost to performance, with emissions down by 12 per cent.
Hyundai Motor Company has revealed a new 1.6-litre turbo petrol engine featuring world-first technology dubbed Continuously Variable Valve Duration (CVVD).
Set to be launched with the new Sonata sedan later this year, the CVVD system forms part of the company’s ‘Smart Stream’ engine and transmission family, which aim to optimise both performance and fuel efficiency.
“The valve control technology regulates the duration of valve opening and closing according to driving conditions, achieving a 4 per cent boost in performance and a 5 per cent improvement in fuel efficiency. Furthermore, the technology cuts emissions by 12 per cent,” Hyundai said in its press release.
“Typical variable valve control technologies manage the timing of the valve’s opening and closing (as in Continuously Variable Valve Timing – CVVT) or control the volume of air admitted by adjusting the depth of the opening (Continuously Variable Valve Lift – CVVL).”
“Previous variable valve control technologies could not regulate valve duration, as the valve’s closing timing was subordinate to opening timing and could not respond to diverse driving situations. CVVD takes the technology in a new direction by adjusting how long a valve is open,” the company added.
Hyundai says CVVD opens the intake valve from the middle to end of the compression stroke when low engine load is required, for example when the vehicle is maintaining a constant speed on the highway.
By reducing the resistance caused by compression, the company says CVVD improves efficiency.
On the flip side, under high engine load, the intake valve is closed at the beginning of the compression stroke to maximise the amount of air used for combustion, “enhancing torque to improve acceleration”.
First to adopt this technology is the new G1.6 T-GDi ‘V4’ turbocharged petrol engine, which develops 134kW of power and 265Nm of torque.
In addition to CVVD technology, the powertrain features low-pressure exhaust gas recirculation (LP EGR) which Hyundai says further enhances fuel efficiency by returning some of the gas burnt by the engine into the combustion chamber for a cooling effect, and reduces the emission of nitrogen oxides.
Hyundai adds engine friction has been reduced by 34 per cent thanks to the use of new, lower-friction moving parts.
The new CVVD technology will debut in the new-generation Sonata Turbo, due to launch Down Under during the second half of 2019.
As noted above, the 1.6-litre turbo petrol engine makes 134kW and 265Nm. Drive will be sent to the front wheels via an eight-speed automatic transmission.
Kia will debut the CVVD system “later on”, likely to be the next-generation Optima that’s due to be revealed before the end of this year.