In November 2025, Mitsubishi Heavy Industries (MHI) officially launched a new generation of lightweight twin-scroll turbochargers, specifically designed for compact passenger cars in the Asian market. This product precisely meets the region's demand for "small displacement, strong power, and low fuel consumption," as well as regulatory trends. Through systematic upgrades in materials, structure, and control, it addresses the industry's pain points of traditional small displacement turbos, such as "turbo lag at startup and weak adaptability to operating conditions." Unlike conventional turbochargers, the twin-scroll technology employs a divided scroll design that channels exhaust gases from the engine in accordance with the firing order of the cylinders. This design prevents interference between exhaust pulses and maximizes the utilization of exhaust energy. The result is an effective boost pressure established even at low RPMs, allowing for immediate thrust upon acceleration. In scenarios such as urban congestion and cornering, frequent downshifting is unnecessary, leading to a more linear and smooth acceleration. Additionally, more efficient cylinder scavenging and residual gas control provide a foundation for fuel-saving technologies like Miller cycle and high EGR rates, enhancing thermal efficiency while avoiding knock, thus achieving dual optimization of power and fuel consumption. The core of this product upgrade lies in breakthroughs in materials and lightweight design. Mitsubishi Heavy Industries has adopted a new generation of high-temperature alloys for hot-end components like the turbine housing, balancing high-temperature strength, oxidation resistance, and thermal fatigue performance. The wall thickness of the turbine housing has been further optimized, reducing the overall weight of the unit (contributing to vehicle weight reduction and lower fuel consumption) while also decreasing thermal stress concentration and enhancing durability under frequent thermal cycling conditions. The rotor system has been optimized in terms of blade design and lightweight materials, reducing rotational inertia without sacrificing efficient operating ranges, significantly shortening boost response times and eliminating the "lag" associated with traditional turbos. The optimized water-cooled center housing and oil circuit design also reduce the risk of oil film carbonization after shutdown, making it suitable for the frequent stop-and-go scenarios typical in congested Asian urban areas. In terms of control and adaptability, this turbocharger is equipped with a high-precision electronic wastegate (EWG) that can accurately regulate boost pressure under real-world driving conditions such as WLTC/RDE, balancing power response and exhaust temperature management. This better protects the three-way catalytic converter and the gasoline particulate filter (GPF), meeting the requirements of the National VIb and subsequent emission regulations. Its efficient operating range covers a broader spectrum of RPMs and loads, making it compatible with the entire range of small displacement engines from 1.0L to 1.5L, facilitating automakers in developing models with different power outputs on the same platform, thus reducing R&D and production costs. For the high-temperature and high-humidity environments in Asia, the product has also optimized thermal shielding and sealing structures, enhancing long-distance stability and compatibility with various fuel grades, including E10 ethanol gasoline. Notably, this turbocharger is also compatible with HEV/PHEV hybrid models. In hybrid systems where "electric drive is dominant and the engine intervenes as needed," its rapid boost response allows for smoother power transitions, avoiding abrupt sensations. Precise wastegate control can also reduce pumping losses, helping the engine operate within a more efficient working range and improving the energy management closed loop of the hybrid system. As the penetration rate of hybrid vehicles in the Asian market continues to rise and emission regulations become increasingly stringent regarding real-world driving conditions, this lightweight twin-scroll turbocharger, which balances power response, fuel consumption, and reliability, will become a core supporting solution for automakers in developing the next generation of compact passenger cars, providing users with a driving experience that offers "big power from small displacement, fuel efficiency, and ease of driving."
