The world’s first Continuously Variable Valve Duration (CVVD) technology has been revealed by Hyundai.
The advantage of CVVD tech is that it optimizes the engine performance and fuel efficiency whilst still maintaining an eco-friendly status.
This is achieved through valve control technology which regulates the duration of valve opening and closing according to driving conditions. It is said to achieve a 4 per cent boost in performance, a 5 per cent improvement in fuel efficiency as well as cutting emissions by 12 per cent.
Traditional internal combustion engines use variable valve control technology that adjusts the timing of valve opening and closing and the depth of the valve’s opening which allows a certain volume of air to enter. Engine power is produced through the fuel intake-compression-expansion-exhaustion cycle.
This system cannot regulate the valve duration in response to a range of diverse driving situations. This is where CVVD technology is different by adjusting how long a valve is open.
If a low engine output is required, such as when maintaining a constant speed, CVVD opens the intake valve from the middle to the end of the compression stroke which helps to improve fuel efficiency by reducing the resistance caused by compression.
If high engine output is required, such as during high speeds, the intake valve stays closed at the beginning of the compression stroke to maximise the amount of air used for the explosion. This action enhances the torque output to improve acceleration.
The first engine to utilize CVVD technology is the new Smartstream G1.6 T-GDi (1.6-litre turbocharged petrol engine) unit that will debut in the upcoming Sonata where it’s tuned to produce 134kW of power and 265Nm of torque.
In addition to the CVVD tech, the new engine also features Low-Pressure Exhaust Gas Recirculation (LP EGR) which further optimizes fuel efficiency. This is achieved by returning some of the gas burnt by the engine to the combustion chamber, producing a cooling effect and reducing the emission of nitrogen oxides.
There is also an Integrated Thermal Management System that quickly heats or cools the engine to an optimal temperature. Engine friction is also reduced by up to 34 per cent thanks to low friction moving parts.
The new G1.6 T-GDi engine will be available locally in the new Hyundai Sonata in the second half of 2019.
More: All News