For its latest tech demonstrator, Subaru
has not only downsized its boxer diesel engine, but has also added powertrain
electrification and vehicle automation into the mix
Subaru’s third iteration of its VIZIV
concept crossover, unveiled at this year’s Geneva Motor Show, features a new
version of Fuji Heavy Industries’ plug-in hybrid diesel powertrain and
showcases the company’s thinking on engine downsizing.
The
4.4-metre long VIZIV-2 concept has been designed as the ideal vehicle to
support urban families with active lifestyles, powered by a 1.6-litre
turbo-diesel ‘DIT’ (Direct-Injection Turbo) Boxer engine, plus three electric
motors
The first VIZIV development, a two door
shooting brake that debuted at the same show exactly a year ago, sported the
familiar horizontally opposed boxer 2-liter diesel unit, while the second-gen
offering, VIZIV Evolution, took last year’s Tokyo Motor Show by storm with a
1.6-liter direct-injection turbocharged (DIT) petrol. VIZIV-2, however, fuses
the best powertrain bits of VIZIV and VIZIV Evolution, with the sleek 4.4m
four-door concept benefiting from a flat-four DIT diesel that’s been shrunk to
1.6 liters.
Three-motor Layout
As with the petrol-electric XV Hybrid now
in production, the VIZIV concepts have a three motor layout to supplement the
drivetrain: one powering the front axle, and two to each of the rear wheels.
These permanent magnet synchronous motors draw energy from a lithium ion
battery pack charged from an external source, essentially from the IC engine
acting as a generator, and by brake energy regeneration. Auto stop/start adds
to the fuel-efficiency, although the electric motors provide much of the
propulsion during low-speed and urban driving.
It
ensures ease and confidence on the road and provides a new level of driving
enjoyment, while increasing the active safety performance typical of every AWD
Subaru model
What isn’t clear, however, is the VIZIV-2’s
all-electric range, as Subaru would not comment on specific data. However, as a
plug-in hybrid, it should certainly be good for short-range hops and for more
than just pulling away at the traffic lights or low-speed manoeuvring,
especially as the Mitsubishi Outlander PHEV, a vehicle that’s similar in
profile and technological setup to the Subaru concept, can travel 51km (32
miles) in its electric-only mode.
The VIZIV-2’s transmission is Subaru’s
Lineartronic CVT, which works with the engine to drive the front wheels, but to
the rear, the two motors distribute torque to each of the back wheels
independently in the symmetrical AWD system. This torque-vectoring is said to
minimize understeer and improve stability.
Also new to this latest VIZIV development
is a three-mode, hybrid-specific version of Subaru’s SI-Drive control system,
enabling the driver to select an ‘eco-cruise’ mode in addition to the original
‘intelligent’ and ‘sports’ settings for the engine and transmission. This works
with the next-generation EyeSight driver assist technology from FHI, which adds
an element of autonomous control – 360° camera taking in data analysis of
traffic conditions ahead – all of which is fed into the powertrain and motor
controls. Interestingly, this is with a view to enhancing and optimizing fuel
efficiency and emissions, as well as for impact-avoidance and safety. The
result, says Tomohiko Ikeda, chief general manager at Subaru and Fuji Heavy
Industries, is remarkable fuel economy levels.
One
year after unveiling the original concept, Subaru has today revealed a new
version of its two-door, four-seater future technology and design showcase
vehicle – the Subaru VIZIV-2 Concept – at the 84th Geneva International Motor
Show
He adds, “The EyeSight driver assist system
is at the heart of automated driving technologies that enhance enjoyment and
peace of mind, and Subaru will continue to innovate in this field.” As a
result, VIZIV-2 not only indicates Subaru’s future thinking in terms of smaller
turbocharged engines, but also demonstrates the increasing focus on interaction
between powertrain and intelligent control/communications technologies.
