Subaru, a division of Fuji Heavy Industries, is one of the smallest Japanese motor manufacturers that produces mostly four-wheel-drive models principally for road use. The VIZIV plug-in hybrid crossover concept unveiled at Geneva was said to show the future direction of the brand. If so, it could signal a move away from conventional four-wheel-drive systems for the company’s products.
Internal-combustion-engine (ICE) power comes from Subaru’s 1998-cm³ flat-four DOHC turbo-diesel, normally rated at 145 bhp (108 kW) and designed principally for the company’s European product range. But the "boxer" engine drives the front wheels only in the VIZIV through a CVT transmission named Lineartronic (Subaru also launched the Outback diesel with Lineartronic transmission at the Show).
An electric motor is integrated with the boxer engine and CVT transmission in a conventional front drive parallel hybrid drivetrain layout. Two further inboard electric motors are fitted at the rear, providing drive to each rear wheel independently. The hybrid system is a plug-in type, while the diesel engine provides charging on the move to the underfloor lithium-ion battery pack.
Subaru terms this Hybrid SI Drive. The motors are used to power the car from rest and provide drive at low speeds, with the diesel engine taking over for highway use. Subaru also hinted that this layout might be adopted for future Subaru all-wheel-drive models, with rear drive provided by electric motors. Subaru refers to this as “Independent-rear-motor-driven symmetrical AWD.” This is effectively a torque vectoring system where the control ECU determines which power sources to use according to needs.
Turning the steering wheel increases the torque delivery to the rear wheels, while turning it back to the straight ahead again increases the front drive bias. The drive system management system assumes the functions of a rear differential and distributes torque between the rear wheels accordingly. So in negotiating a turn, more torque is fed to the outside wheel and less to the inner wheel.
VIZIV is equipped with Eyesight, an onboard system that feeds data to the drive control system. Eyesight uses a forward facing stereoscopic camera. Input from the camera is used to modify engine and motor power output or initiate braking, according to conditions sensed by the camera, with the aim of improving safety and reducing environmental impact. Three driving modes are offered: Eco-Cruise, Intelligent, and Sports.
In stop-start urban traffic, both diesel engine and electric motors are used to start the vehicle from rest to provide high starting torque, while helping to reduce fuel consumption and engine noise.
The VIZIV is a four-seat crossover concept equipped with a single forward hinged blade-type door on each side. The projecting front grille and steeply raked windshield help to reduce the frontal area. Inside, the Eyesight cameras are positioned high behind the windscreen, while the rev counter and speedometer are positioned ahead of the driver. Other information is displayed on screens above the center stack, including information from the Eyesight cameras. Screens also relay similar information to both front and rear passengers.