2015-SONATA-0034

Hyundai has announced a new six-speed automatic transmission for hybrid electric vehicles (HEV) at the company’s annual International Powertrain Conference in Namyang, South Korea.

The new six-speed automatic gearbox integrates the electric motor and is said to apply a number of new technologies that deliver tangible benefits to the customer. The new unit will be fitted to future Hyundai hybrids, including the upcoming new Sonata Hybrid.

The set-up means that almost all of the hybrid powertrain components are contained within the transmission, minimising energy losses and increasing fuel economy.

A new traction motor and electric oil pump (EOP) have been fitted, while the torque converter has been removed completely. A lighter torsion damper, and new engine clutch, which features fewer clutch discs, reduce drag and contribute to a more efficient transfer and use of power.

The most significant change is within the oil pump system. It achieves improved fuel efficiency by removing the mechanical oil pump causing hydraulic losses and by applying a new electric oil pump which automatically optimises the system according to driving conditions.

With fewer components, the new transmission weighs 130 kg (wet) – making it lighter than its previous version – yet still delivers 280 Nm of torque.