Original name: スバル B5-TPH

Development objective

A new-generation crossover vehicle with a hybrid power train system

The Subaru B5-TPH concept car develops the theme of crossover elements in a future car -a crossover between a gasoline engine and electric motor, and between a sport wagon and sport utility vehicle (SUV). Incorporating Subaru's signature Symmetrical AWD, the concept car provides a glimpse of a future sport specialty car that further enriches the driving experience.

Major features of the B5-TPH

The Turbo Parallel Hybrid (TPH) power train, a new AWD hybrid system, has been applied in the B5-TPH. Subaru has beer developing the TPH with advanced, integrated Symmetrical AWD in view of its future mass production.

By combining the electric motor and the Miller cycle boxer turbo engine (2.0L), the TPH system not only provides powerful and pleasurable driving in the mid-to high-speed ranges when the turbocharger is active, as with conventional turbo models, but it also delivers excellent acceleration and fuel economy in all ranges. This superb, all-range performance is enabled by the motor assist feature, a motor that is designed to boost engine torque at low revolutions.

The TPH system places a thin motor generator between the vehicle's engine and its automatic transmission. This simple hybrid configuration makes possible the ideal weight balance of a vehicle, equal to the balance realized by Symmetrical AWD in a gasoline-only engine. Benefiting from the superb drivability guaranteed by Symmetrical AWD and the all-range smooth delivery of torque, the B5-THP ensures sporty, high quality performance.

The concept car promises versatile handling and maneuverability both on and off the road with its ground clearance of 200 mm and large-diameter tires.

Besides featuring functionality, the B5-THP designs express the pleasure of driving, and of being driven as a passenger. Blending beautiful lines and the characteristics of the sport wagon, personal coupe and SUV, the car accentuates the crossover of its designs and function.

Turbo Parallel Hybrid


The TPH is a simply structured, parallel hybrid system, connecting a thin motor generator directly onto the crankshaft of a gasoline turbo engine. The system improves on fuel economy in practical driving ranges, thanks to the combined effects of the Miller cycle boxer turbo engine and the motor assist feature of the electric motor. The motor assist also solves a problem inherent to a turbo engine, which is a lack of torque at low speeds. The TPH system has advanced the current turbo engine to the next-generation turbo engine with all-range performance.

At the same time, the TPH takes full advantage of the Symmetrical AWD layout, further heightening the levels of driving pleasure and performance, while reducing energy consumption and contributing to environmental conservation.

Other features

2-liter,  Horizontally-Opposed, 4-cylinder, DOHC, Miller-cycle turbo engine

Through valve opening modifications in the Active Valve Control System (AVCS) of the 4-cylinder boxer turbo engine, the adopted Miller cycle principle delays the closure of the Intake valve. The Miller cycle contributes to improvements in fuel economy in practical driving ranges. The issue of lower power output with the Miller cycle, on the other hand, has been resolved by improvements in the turbocharger system. While retaining the attractive character of powerful output from a turbo engine at high revolutions, the engine has achieved fuel economy improvements and reduced CO2 emissions.

Motor generator

Placed between the vehicle's engine and its AT torque converter, directly connected to the crankshaft, a thin motor generator plays an important role in boosting the engine's torque at low revolutions. By integrating such critical functions in the motor as propelling the wheels, electricity generation and battery recharging during regenerative braking, FHI has successfully developed the hybrid AWD power train system. Without compromising on the stable, agile driving and crash safety ensured by uninterrupted Symmetrical AWD structure, the hybrid system has strong environmental advantages.

Power control unit

The control unit for the motor inverter is packaged in a compact layout, which comprises the Intelligent Power Module (IPM), DC-DC converter, motor controller, and condenser, and is placed in the engine room, filling the space where a 12-V battery is usually located in a gasoline vehicle.

Battery pack

The B5-TPH is equipped with a manganese lithium-ion battery pack, which powers the motor generator. Compared to the nickel-metal hydride battery that is widely used for many hybrid electric vehicles, the manganese lithium-ion battery excels in tolerable charge/discharge electric power density, longevity, and is compact and lightweight. The battery pack is designed in all-in-one packaging with an electronic control unit for the battery, which facilitates its mounting onto the back of the vehicle, while taking safety measures against high voltage hazards and considering ease of maintenance.



A crossover theme is adopted for the B5-TPH concept car by blending fun-to-drive styling and functionality. The styling emphasizes both elegance and power, perfectly suited to any driving conditions, while the B5-TPH is fully equipped with functional and convenient utilities to augment the fun of traveling.

Major features Outback-based styling

The design of the B5-TPH concept car has progressed from the basic form of the Subaru Outback, a crossover sport utility vehicle that combines the rugged versatility of an SUV and the sporty handling and comfort of a passenger car. The new sporty 2-door coupe features a streamlined coupe wagon style body and incorporates design elements that ensure versatile driving capabilities without any limitation. Despite its elegant profile, the car also expresses powerful drive train performance in its styling, which is conceived on the theme of a new-generation crossover vehicle with an environmentally friendly, hybrid power unit, widening the scope of driving opportunities in harmony with nature. A minimum road clearance of 200 mm and large-diameter tires are practical design features that heighten superb stability and drivability.

*The Outback was introduced in the U.S. and Australia as a variation of the second-generation Legacy in 1995. The same variation model was named the Legacy Grand Wagon In Japan In that year, and then renamed the Legacy Lancaster in 1997. Since 2003 Outback has been used worldwide.

New-generation Subaru design

The concept of the new-generation Subaru design was first introduced in the Subaru B11S concept car in 2003. Since then it has continued to evolve and has been adopted in the B5-TPH. Combining glamour and functionality, the silhouette of this new car projects a sophisticated coupe wagon style, while brining out casual sportiness and elegance. A wide glass canopy covers open, sun-filled interior space, which highlights an ideal balance of functionality and comfort, and has been designed around the concept theme of a car for long-weekend getaways for couples of any age.

Clam-shell-shaped rear gate opening

The large rear gate opens fully, like a clam shell. The wide glass hatch is intended to show luggage inside the trunk space, accentuating the theme of a couple's traveling car and visually stressing the fun of long-distance driving.

Body color

Named vital lunar pearl white, the color that envelops the car body is similar in tone to ivory. The color appears warm and elegant, yet under bright light or sunshine, it changes to bring out strong moonlit undertones, and the basic tone reveals a variety of hues within a spectrum of highlights, enhancing the B5-TPH's sporty image. This feature further echoes Subaru's crossover diversity concept.


4465 mm


1820 mm


1500 mm


2670 mm

Ground clearance:

200 mm

Curb weight:

1380 kg

Maximum passenger

4 people

TIRES size

245/45 R19


Manganese lithium-ion batteries box


Nominal voltage


Nominal capacity


Outside size (except for fan)



670 mm


360 mm

Height: 180 mm



32 kg


SUBARU BOXER 2.0-liter H4 Turbo charged engine


Engine type

Petrol DOHC 16 valve Dual AVCS
(Active Valve Control System)
twin scroll turbo charged engine
(miller cycle)

Comperssion ratio



191 kW / 260 hp @ 6000 rpm


343 Nm @ 2400 rpm

Fuel economy

17 km / liter


Motor generator specifications


Motor type

Permanent-magnet type
synchronous motor

Maximum traction power

10 kW

Maximum traction torque

150 Nm

Maxiumum generating electric power

8.5 kW


SOURCE: Subaru. Please mention www.allcarindex.com if you use this text.