Hyundai Continuously Variable Valve Duration (CVVD) tech will soon be a feature in future Hyundai and Kia vehicles. Hyundai CVVD optimizes engine performance and fuel efficiency. Valve control tech takes care of valve opening, and closing duration as per driving condition. In doing so, CVVD attains 4 percent performance boost, and 5 percent fuel efficiency. There’s also 12 percent emission reduction.
Typically, internal combustion engine’s (ICE) performance and efficiency is dependent on variable valve control tech. This is the process of adjusting the timing of valve opening and closing. And depth of the valve opening. Engine power is an outcome of the fuel intake-compression-expansion-exhaustion cycle.
In general, variable valve control tech manages valve opening and closing timing continuously, i.e, Continuously Variable Valve Timing (VVT). This is done by controlling volume of air admitted through depth of the opening adjustment (Continuously Variable Valve Lift – CVVL).
Earlier variable valve control tech wasn’t adept at regulating valve duration. This is because valve’s closing timing was subordinate to opening timing. And the tech simply couldn’t respond to varied driving conditions.
CVVD is capable of adjusting how long a valve is open. At constant speed, a vehicle requires low engine output. CVVD then opens intake valve from the middle to end of the compression stroke. As such, fuel efficiency is improved by reducing the resistance caused by compression.
At high speed, when engine output is required to be high, Hyundai CVVD tech ensures the intake valve is closed at the beginning of the compression stroke. This maximises amount of air used for the explosion. And enhances torque to improve acceleration.
Smartstream G1.6 T-GDi engine is a V4 gas turbo unit that returns 180 hp, and 27.0kgm of torque. It’s exhaust gas recirculation system returns some of the gas burnt by the engine to the combustion chamber. This brings about a cooling effect and reduces emission of nitrogen oxides.
The G1.6 T-GDi low-pressure system redirects burnt emission gas to the front of the turbocharger compressor. Not to the intake system. This improves efficiency under high load condition.
An Integrated Thermal Management System heats or cools the engine quickly to reach optimal temperature. A strong direct spray system achieves 350bar. The prebious T-GDi engine got to 250br.
Engine friction reduction is at 34 percent. For this, low friction moving parts have been used. Hyundai Sonata Turbo when introduced in H2 2019 will be the first vehicle to feature the Smartstream G1.6 T-GDi engine.