Hyundai, Kia shift gear on hybrids

HYUNDAI Motor Group (HMG) has developed a new type of automatic transmission for hybrid drivelines that overcomes the slower shift times caused by a lack of torque converter in conventional systems and will debut in the eighth-generation Sonata mid-size sedan.

The Sonata is confirmed to be powered by a 2.5-litre petrol engine when it arrives in Australia during the fourth quarter of this year, but Hyundai Motor Company Australia PR senior manager Guido Schenken told GoAuto that the hybrid was also under review for this market.

HMG claims its new Active Shift Control (ASC) technology can reduce gear shift times by 30 per cent – from 500ms to 350ms – and says the system will be rolled out across future hybrid models from Hyundai and sister brand Kia.

While some hybrid drivelines from the likes of Toyota and Honda use a continuously variable transmission, those using a conventional stepped-ratio set-up do away with the torque converter in order to minimise energy losses.

The downside of losing the torque converter is a slowing of gear shifts in order to maintain smoothness, which HMG says is overcome by the extra precision of ASC technology.

ASC uses a sensor inside the electric motor to monitor transmission rotation speed at a rate of 500 times per second so it can quickly and accurately synchronise revs between the combustion engine, electric motor and transmission.

As well as quicker, crisper, smoother gear shifts, HMG says the new system improves acceleration and driving pleasure while reducing fuel consumption and friction; the latter having the side benefit of boosting durability.

HMG vice president and head of powertrain control system group KyoungJoon Chang said the transmission tech would “not only save fuel but also provide a more fun driving experience for our customers”.

“The development of world’s first ASC technology is a remarkable innovation which incorporates precise motor control to automatic transmission,” he said.

As reported, the new Sonata Turbo will debut an all-new 1.6-litre V4 engine featuring continuously variable valve duration for improved power and efficiency.