Hyundai Motor and PHA ‘Lightweight Stand-alone Power Trunk’
ėŽė§ íë From left, Kim Do-hyung, head of Hyundai Motor, Lim Yong-hyuk, lead researcher, Hong Seong-tae, lead researcher at PHA, and Kim Doo-jung, lead researcher.
The “small and lightweight standalone power trunk system” developed by Hyundai Motor and parts company PHA won the IR52 Jang Young-sil Award in the 30th week of 2026. It is an innovative technology that has greatly expanded the automatic trunk opening and closing function, which was previously considered the exclusive property of large sedans, to small car class.
With the opening of the electric vehicle era, vehicle weight reduction and indoor space optimization for power efficiency have emerged as key challenges. However, due to the bulky and heavy existing power trunk system and the complex structure that requires brackets and springs to be fixed in various parts of the vehicle, it was difficult to mount in a small car.
The two companies started developing with the awareness of the problem, “Can we provide the convenience of a power trunk as much as a large sedan in a small car?” As a solution to this, the company devised a “standalone technology” that completely eliminates body fixing parts by installing a driving device directly on the trunk joint (hinge arm).
As power transmission efficiency is maximized, it is possible to implement smooth opening and closing operations even with small motors with 33% lower output than conventional ones. Through this, we succeeded in reducing the overall weight of the system by 70% from 3.0kg to 0.9kg. In addition, the quietness during operation has also been raised to the world’s highest level by installing a drive device independently at the joint position where noise and vibration are least transmitted indoors.
With the disappearance of body fixing parts and complex structures, trunk loading space has increased to 465 liters, the highest level among the world’s equivalent vehicles. By maximizing space utilization to 72.1%, it has even caught the recent increase in demand for camping and outdoor leisure activities.
Lim Yong-hyuk, a senior researcher at Hyundai Motor’s MSV Closure Design Team 2, who led the development, said, “There is an opportunity to provide convenience functions for power trunk to more models,” adding, “We plan to apply and expand it to various loading space technologies such as the Prunk (front loading box) Power trunk system of electric vehicles in the future.”
Starting with Hyundai Motor’s global small electric vehicle “EV4,” this product will be applied sequentially to major lineup. The proportion of exports to overseas automakers will also be gradually expanded. It made its first sales of about 3.3 billion won last year, and is expected to generate more than 150 billion won a year within a few years.