A better mousetrap – i.e. Valvetrain control, from the minds at Hyundai. Wayne Gerdes – CleanMPG – July 3, 2019 Hyundai will soon be releasing an all-new and unique valvetrain control technology that is designed to meet a wider variety of driving conditions. Hyundai calls it Continuously Variable Valve Duration (CVVD). The innovation was revealed within the brands Smartstream G1.6 T-GDi, the first engine to feature the technology and slated to be inside the all-new 2020 Sonata (ECO trim possibly?) this fall. CVVD optimizes both engine performance and fuel efficiency. The valve control technology regulates the duration of valve opening and closing according to driving conditions, achieving a 4% boost in performance and a 5% improvement in fuel efficiency while also reducing overall SMOG forming emissions by 12%. Continuously Variable Valve Duration An internal combustion engine’s performance and efficiency have been governed by variable valve control technology that adjusts the timing of valve opening and closing and depth of the valve’s opening, with engine power produced through the fuel intake-compression-expansion-exhaustion cycle. 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. When the vehicle is maintaining a constant speed and requires low engine output, CVVD leaves intake valve open until the middle and closes the valve near the end of the compression stroke. Aka, a fully atkinsonized low torque intake topology. This helps to improve fuel efficiency by reducing the resistance caused by compression, aka pumping losses. When high engine output is demanded, such as when the car is driving at a high speed, the intake valve is closed at the beginning of the compression stroke to maximize the amount of air used for the explosion, enhancing torque to improve acceleration. Smartstream G1.6 T-GDi Engine Unveiled alongside the new CVVD technology is the new Smartstream G1.6 T-GDi Engine, a I4 gasoline turbo unit with 180 hp and 195 lb-ft of torque. The new powertrain is the first to utilize the Group’s new CVVD technology and also features Low-Pressure Exhaust Gas Recirculation (LP EGR) to improve fuel efficiency further. 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 the high load condition. 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 5,076 psi, surpassing the 3,626 psi of the current T-GDi engine. The newly design engine engines friction has reduced by 34% with the application of low friction moving parts. The new Smartstream G1.6 T-GDi engine will be available in the 2020 Hyundai Sonata 1.6L Turbo set for introduction in the second-half of this year. 2020 Hyundai Sonata with the Smartstream G1.6 T-GDi cutaway 2020 Hyundai Sonata Eco - Early Conclusions The current Sonata Eco with the 1.6L GDI-T mated to the 7-speed DCT achieves a 28/37 mpgUS city/highway rating. Might we see a 29/39 mpgUS city/highway rating in a 2020 Sonata Eco model with it, the Smartstream G1.6 T-GDi, inside? This result would edge out the already fantastic 40 + percent thermodynamically efficient 2.5L I4 in the Camry LE/XLE (28/39 mpgUS city/highway) but will probably still fall behind the super-efficient base 2019 Camry with its segment leading and sky high 29/41 mpgUS city/highway rating. Easily achieved which I might add. Oh how I would have loved to have been working on this Valvetrain project at Hyundai and I cannot wait to drive one.