"2.5 Turbo hybrid had to be different."
The core of the Hyundai Motor Group's next-generation hybrid system is high output and high efficiency. I wanted to connect the hybrid to a 2.5 Turbo engine, not a 1.6 Turbo. At the same time, it was necessary to balance efficiency comparable to that of a 1.6 Turbo.
The practical reason that Hyundai Motor Group had to develop the next-generation hybrid was ultimately the larger size of hybrid vehicles. While it was able to sustain the Hyundai Staria and Kia Carnival with a 1.6 Turbo hybrid, there were limits for larger vehicles.
Engineers at Hyundai Motor Group found the answer to the next-generation hybrid system in "two motors." Many global corporations operating hybrids have adopted the "two motors" method.
The approach was similar, but Hyundai Motor Group took a step further. It directly integrated the P1 motor into the engine. Compared to the common method of a P0 motor connected to the engine by a belt, this reduced friction loss. The structure of the transmission with two motors was also optimized. As a result, the next-generation system was born with 19% higher maximum output and 45% improved fuel efficiency compared to conventional internal combustion engines, allowing for hybrid systems in mid-sized vehicles achieving over 300 horsepower.
The significance of the next-generation hybrid system is substantial. It has enabled a strategic portfolio based on a multi-powertrain. Large hybrid vehicles are essential in an unstable electrification market.
Hyundai Motor Group unveiled its next-generation hybrid system to media representatives on the 10th. At the "Hyundai Motor Group Next-Gen Hybrid System Tech Day" held at 'Crest 72' in Jung-gu, Seoul, it revealed its evolved hybrid technology.
At the event, Hyundai Motor Group announced that it developed the next-generation hybrid system under the concept of "perfect harmony of power and efficiency, hybrid and more than an electrification experience (Well Balanced High Tech & Expanded xEV Experience)."
The next-generation hybrid system from Hyundai Motor Group can combine various engine lineups with a new transmission that contains two motors, providing optimized performance and fuel efficiency according to vehicle class and characteristics. It applies various electrification specialized technologies to improve driving performance, ride comfort, and enhance the in-vehicle experience.
The newly developed next-generation hybrid system transmission incorporates a new motor (P1) responsible for starting, generating, and assisting drive force, in addition to the drive motor (P2) responsible for drive and regenerative braking, improving power performance and fuel efficiency while also realizing smooth shifting and reducing noise and vibration.
The next-generation hybrid system transmission, combined with Hyundai Motor Group's diverse engine lineup, offers system output coverage ranging from just above 100 horsepower to mid-300 horsepower, enabling a wide range of operations from small to large vehicles. Moreover, Hyundai Motor Group leverages its extensive hybrid development experience and motor and battery control technologies accumulated through the development of the dedicated electric vehicle platform E-GMP to enhance driving performance and ride comfort while providing electrification conveniences such as stay mode, vehicle-to-load (V2L), and smart regenerative braking that were previously experienced in electric vehicles.
Han Dong-hee, vice president in charge of electrification development at Hyundai Motor Group, stated, "Hyundai Motor Group has developed an innovative new hybrid system that integrates the engine, transmission, and hybrid system development experience accumulated over a long time with world-class electrification technologies applied to the best electric vehicles. We will continuously develop innovative technologies that actively utilize electrification technology during the transition to electric vehicles and provide customers with environmentally friendly and high-performance vehicle experiences."
▲New transmission with two integrated motors
Hyundai Motor Group has completed the structure of 'P1+P2 parallel configuration' in the next-generation hybrid system transmission by newly adding a starting motor (P1) that performs starting, generating, and assisting drive force alongside the drive motor (P2) responsible for drive and regenerative braking. The P1 motor, directly integrated into the engine, has higher energy transmission efficiency with no friction loss compared to the P0 motor connected to the engine via a belt in existing hybrid systems and improves both fuel efficiency and power performance by assisting the vehicle's drive force along with the P2 motor according to driving conditions.
Additionally, Hyundai Motor Group has increased the allowable torque of the next-generation hybrid system transmission from 37.4 kgf·m to 46.9 kgf·m, approximately 25%, allowing for a natural and powerful output of maximum torque when combined with high-displacement turbo engines. Despite adding the P1 motor and increasing the allowable torque of the transmission, the next-generation hybrid system transmission maintains the same size as existing levels, making it applicable to a wide range of vehicles from small to large.
Hyundai Motor Group improved the cooling structure and flow rate of the P1 and P2 motors, increasing the power density per unit volume by about 21% and the torque density by about 7%, while optimizing the arrangement and size of key components such as dampers and electric oil pumps (EOP), thus reducing the overall transmission volume and ensuring the expandability for various vehicle classes.
▲ Maximized efficiency of 2.5 Turbo hybrid
Hyundai Motor Group developed the gasoline 2.5 Turbo hybrid engine as the first powertrain of the next-generation hybrid system, improving the design and control technologies of the existing 2.5 Turbo engine to maximize efficiency.
The 2.5 Turbo hybrid engine features a newly added P1 motor between the transmission and engine that is responsible for the engine's starting and generating, allowing for the removal of unnecessary main belts, alternators, and air compressor that used to dissipate power from the vehicle drive, minimizing power losses, and enhancing performance and efficiency through the introduction of a high-efficiency cycle optimized for hybrids and strengthening the flow of the mixture inside the cylinder.
Generally, internal combustion engines obtain power through the 4-stroke cycle of intake, compression, explosion, and exhaust. Hyundai Motor Group applied an "over-expansion cycle" by intentionally delaying the closure of the intake valve during the compression stroke, lowering the effective compression ratio of the mixture that entered the cylinder while maintaining a high expansion ratio during the explosion process. As a result, power consumed during mixture compression decreases, and energy generated after combustion is maximized, further enhancing engine performance and efficiency.
Additionally, improvements in piston shape and significant expansions in the three-stage injection areas of fuel have enhanced engine efficiency in various aspects, including combustion speed enhancement, combustion stability assurance, and knocking suppression.
▲ Fuel efficiency improved by 45% and maximum output increased by 19% compared to conventional internal combustion engines
Through improvements in transmission and engine centered around the 'P1+P2 parallel configuration', Hyundai Motor Group has enhanced both fuel efficiency and power performance while achieving smooth shifting and improved quietness. The integration of the P1 motor directly into the engine has reduced the time it takes to start the engine and decreased fuel consumption, while precision control of the engine load and drive forces of the P1 and P2 motors ensures that the engine operates within high-efficiency ranges, thereby enhancing the efficiency of 'road leveling'.
The gasoline 2.5 Turbo hybrid, equipped in large SUVs, boasts a maximum fuel efficiency of 14.1 km/ℓ, a system maximum output of 334 horsepower, and a maximum torque of 46.9 kgf·m, which compared to conventional 2.5 Turbo gasoline models has approximately 45% better fuel efficiency and increases maximum output and maximum torque by about 19% and 9%, respectively. (Based on the Palisade 2WD 7/9 passenger model with 18-inch wheels)
The gasoline 1.6 Turbo next-generation hybrid has improved fuel efficiency by approximately 4.3% compared to previous models for mid-sized SUVs, while the allowable torque of the transmission has increased from 37.4 kgf·m to 38.7 kgf·m, boasting an even better acceleration response. Furthermore, the hybrid shifting logic 'ASC (Active Shift Control)' has utilized the P1 motor for faster and smoother shifting performance than before, and enhancements in engine clutch control have reduced the discomfort caused during engine engagement while operating in 'EV mode', improving ride comfort.
In situations where the engine drives to charge the battery while stationary, a new technology has been applied to reduce engine vibrations and booming using the P1 motor, enhancing interior quietness.
▲ Improved driving performance by utilizing electrification technologies
In addition to the new hybrid powertrain that enhances performance and efficiency, Hyundai Motor Group has applied various electrification-specific technologies to hybrid vehicles to secure product competitiveness.
On this day, Hyundai Motor Group presented a lineup of electrification-specific technologies consisting of e-AWD, e-VMC 2.0 (Electrification-Vehicle Motion Control), stay mode, V2L, and smart regenerative braking. All these technologies were obtained during the development process of electric vehicles.
e-AWD is an electronic four-wheel-drive system that enhances driving performance and acceleration response by adding a drive motor (P4) to the rear axle of front-wheel-based hybrid vehicles. Hyundai Motor Group plans to operate both e-AWD and existing mechanical four-wheel drive, applying the optimal four-wheel drive systems suited to vehicle class, characteristics, and market environments.
e-VMC 2.0 is an improved system based on the performance of the existing e-VMC.
e-VMC 2.0 is a technology applied to hybrid vehicles based on e-AWD, which increases driving stability and ride comfort through independent torque control of the front and rear drive motors, comprising e-handling 2.0, e-EHA (Electrification-Evasive Handling Assist) 2.0, and e-ride 2.0.
e-handling 2.0 is a technology that strengthens roll prevention performance by controlling the front and rear motors in opposite directions while turning, lowering the vehicle's center of gravity. While the existing E-handling improved driving stability and responsiveness through acceleration and deceleration control of a single motor, the 2.0 version offers a more refined control for an enhanced driving experience.
e-EHA 2.0 is an emergency steering assist technology that utilizes the vehicle's radar and camera sensors to detect forward collision risks and provides more precise assistance for evasive maneuvers through braking control of the front and rear motors during the driver's abrupt steering. Particularly, when the vehicle enters a stable phase after an emergency steer, the front motor takes over driving, and the rear motor handles braking, lowering the vehicle's center of gravity and improving roll performance.
e-ride 2.0 minimizes the up-and-down movement of the vehicle when passing over speed bumps to maximize ride comfort. It utilizes changes in the vehicle's center of gravity through opposite direction control of the front and rear motors during entering and exiting speed bumps, reducing pitch and bounce motion.
Stay mode applies the 'utility mode' of electric vehicles to hybrid vehicle characteristics using high-voltage batteries, allowing customers to have a more comfortable time inside the vehicle when it is stationary before and after driving. In stay mode, all in-vehicle comfort features, including climate control and multimedia, can be used without starting the engine, and it can be utilized for up to one hour when the battery charge is at 70-80%. (※ Stay mode duration may be reduced depending on power consumption.)
Considering that the high-voltage battery capacity of hybrid vehicles is relatively less than that of electric vehicles, Hyundai Motor Group has introduced a 'stay mode usage reservation upon arrival at the destination' feature. This function is linked with navigation, starting battery charging about 2 km before reaching the destination, ensuring that the battery charge is at 70-80% upon arrival to maximize stay mode usage time.
The V2L applied to the next-generation hybrid system supports up to 3.6 kW of maximum output, providing diverse electrification experiences in situations such as camping and parking. V2L can be continuously used when the engine is running, and in stay mode where the engine is not operating, it can utilize up to 50% of the battery capacity (from 80% SoC down to 30%).
Hyundai Motor Group enhances fuel efficiency further through hierarchical predictive control technology (HPC) and smart regenerative braking. HPC predicts the driving route and road conditions to optimally control the battery charge, leading to the operation of driving modes optimized for fuel efficiency (EV mode, hybrid mode, regenerative braking mode, etc.) for each route.
Smart regenerative braking is a feature that automatically applies the optimal regenerative braking strength based on comprehensive assessments of navigation data such as speed cameras and inter-vehicle distances. This reduces the driver's braking pedal operations, lowers driving fatigue, and helps increase battery charge through regenerative braking, thereby improving fuel efficiency.
▲ Full hybrid lineup from small to large and luxury vehicles
Hyundai Motor Group has achieved system output coverage from just above 100 horsepower to mid-300 horsepower by combining the new hybrid transmission with Hyundai Motor Group's various engines, and plans to showcase a variety of hybrid vehicles ranging from small to large and luxury.
With the expansion of system output coverage, the hybrid powertrains will increase from three to five types, among which the 2.5 Turbo hybrid will be first applied to the Hyundai Palisade hybrid, which started mass production this month, and subsequently to other Hyundai and Kia models.
Moreover, Hyundai Motor Group plans to introduce a rear-wheel drive 2.5 Turbo hybrid in 2026 and sequentially equip it in major Genesis models, expanding the hybrid lineup to luxury brands.
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