Hyundai has unveiled the hybrid version of the all-new Sonata sedan in Seoul, Korea, with the model’s highlight being the fuel consumption of 18.2 km/l (5.5 l/100 km or 42.8 mpg US).

Hyundai says the new Sonata Hybrid features a unique hybrid design with an upgraded powertrain that delivers “class-leading” fuel economy. The hybrid system combines a 2.0-liter GDI gasoline engine with a 38 kW (51hp) electric motor. The gasoline engine produces 156PS (154hp) and 190 Nm (140lb-ft) of torque. Compared to the previous model, power and torque are up 4 percent and 5.5 percent respectively.

The electric motor also delivers 8.6 percent improved maximum power, with maximum torque of 205Nm (151lb-ft). The electric motor is fed by a lithium-polymer battery pack with a capacity of 1.62 kWh, 13.3 percent higher than the previous model’s 1.43 kWh. The battery has been relocated under the floor of the trunk, allowing for a flat trunk floor. Thanks to this, Hyundai says the cargo area is more usable and 10.5 percent larger.

The gasoline engine sends power to the road via a six-speed automatic transmission. The gearbox is fitted with a traction motor, while the torque converter has been removed. A lighter torsion damper, and new engine clutch with fewer clutch discs reduce drag and contribute to a more efficient transfer and use of power.

The Korean automaker says it has invested 27 months and approximately 180 billion Won ($164 million) in the development of the new Sonata Hybrid. The model will launch in major markets outside Korea from the first half of 2015, with Hyundai targeting 55,000 sales for next year: 18,000 in Korea and 37,000 overseas. The US-spec model will debut at the Detroit Auto Show next month.

The new Hyundai Sonata Hybrid will also spawn a plug-in hybrid variant next year, which will be Hyundai’s first ever PHEV. The carmaker also plans to introduce its first dedicated hybrid model in the second half next year.

PHOTOS