liter 2 cylinder hybrid
(from Toyota Press
Release) TOYOTA ENGINEERS A SUPER-EFFICIENT AND AFFORDABLE
HYBRID FUTURE WITH THE FT-Bh CONCEPT
• New Toyota concept
targets minimised emissions from a vehicle that uses
economically viable technologies and manufacturing methods
• Longer than a Yaris, but 25 per cent lighter thanks to
• High aerodynamic efficiency, with 0.235 drag coefficient
• Full hybrid powertrain featuring high-efficiency two-cylinder
1.0-litre petrol engine
• Average134.5mpg and 49g/km CO2 emissions – new performance
benchmarks for a full hybrid vehicle
• Flexibility of Toyota Hybrid Synergy Drive gives potential for
future compressed natural gas hybrid and plug-in hybrid versions
with even lower carbon emissions
• World premiere at the Geneva motor show
Toyota’s new FT-Bh
concept is a vehicle designed to take the efficiency of full hybrid
vehicles to new heights. Making its debut at the Geneva motor show,
it is an ultra-light concept, weighing less than 800kg, which
demonstrates what can be achieved in terms of fuel consumption and
CO2 emissions in an affordable family supermini.
Thanks to its low weight, exceptional aerodynamic quality, very low
driving resistance and its highly efficient powertrain, FT-Bh can
achieve an average 134.5mpg fuel consumption and 49g/km CO2
Those figures are from a vehicle that is close in size to today’s
Yaris, at 3,985mm long, 1,695mm wide and 1,400mm tall, with a
2,570mm wheelbase. The emissions are about half the level of those
produced by a 1.0-litre Yaris.
In their mission to achieve the best possible fuel economy and
emissions, the design team focused on five key areas: reducing
weight; driving resistance (including aerodynamic and tyre
performance); powertrain efficiency; thermal energy management; and
Toyota recognises that a real-world reduction of total global
vehicle CO2 emissions can only be brought about if an affordable,
ultra-low emissions vehicle can be manufactured and sold in
sufficiently high volumes. That made it important that the concept
did not require exotic, expensive materials or complex manufacturing
procedures, but used instead only those that are already commonly
available in the motor industry.
“Ecomotion” was the
theme for styling FT-Bh, with its shape demonstrating a new approach
to bodywork design. Key panels, such as the roof, are formed to
represent the way fabric can be stretched taut between fastening
points, to reflect their ultra-light weight.
The front end of the car broadcastsToyota’s current design language
with its large lower grille, together with a sculpted bonnet and
headlamps that are integrated into the front wings. Ultra-slim A and
C-pillars maximise the glazed area for better visibility and a
greater sense of space in the cabin.
The way in which the cabin merges seamlessly into the rear of the
vehicle, with an uplifted rear bumper and chevron-shaped corner
elements, helps achieve the best possible aerodynamic performance
and deliver a drag coefficient of just 0.235.
The stretched fabric-look carries through to the minimalist
interior, with a concave centre console creating a driver-focused
cockpit, while maintaining the overall feeling of light and space.
The target for FT-Bh was
a 25 per cent saving on the 1.0-litre Yaris’s 1,030kg kerb weight.
Using a combination of high-tensile steel, aluminium and magnesium
in the construction has trimmed the weight to just 786kg.
In fact, because the hybrid powertrain is heavier than the
three-cylinder 1.0-litre engine (weighing about 60kg), the combined
mass of the bodyshell, interior trim, chassis and electronics had to
be reduced by around 340kg – one third of Yaris’s weight – to
achieve the target.
Such a large saving in the weight of cabin parts has had a ripple
effect in weight reduction in the rest of the vehicle. For example,
it means there is less load applied on the body structure and
suspension, allowing components to be downsized. And less weight
means a smaller displacement engine can be used, further saving
weight and thermal energy losses.
FT-Bh’s full hybrid
drive system is a masterpiece of powertrain downsizing. With
substantial weight savings in every driveline component, it is
almost 90kg lighter than theHybrid Synergy Drivesystem used in
The lightweight, two-cylinder, 1.0-litre Atkinson cycle petrol
engine combines high efficiency with low thermal capacity and
benefits with detailed measures to increase combustion efficiency
and reduce friction. As a result, FT-Bh achieves an average fuel
consumption of 134.5mpg and CO2 emissions of just 49g/km.
The car’s light weight makes it agile and responsive to throttle and
brakes, and thanks to its electric motor delivering maximum torque
from standstill, it is nimble, too.
FT-Bh demonstrates the adaptability of Toyota’s Hybrid Synergy
Drivetechnology. It serves as a study for how even greater fuel
efficiency might be achieved in the medium term by using two
alternative powertrains: a compressed natural gas hybrid (CNG-HV),
with 38g/km CO2 emissions; and a Plug-in hybrid (PHEV), emitting
Lower driving resistance
The concept represents a
comprehensive study in next-generation aerodynamic techniques. It
features air curtain intakes on the frontal extremities of the
bodywork; air-stream alloy wheels; the replacement of
airflow-disrupting door mirrors with cameras; latches in place of
handles to open the doors; a pagoda-style roof with a dropped rear
section; and a sharply cut rear end that incorporates an air outlet
slit and an underfloor spoiler to smooth the flow of air away from
Together these measures bring the Cd down from a B-segment/supermini
average of about 0.29 to just 0.235.
FT-Bh rides on narrow, large diameter 145/55R18 low rolling
resistance tyres, which make a significant contribution to bringing
down the road load and driving resistance, with no loss of grip or
Thermal energy management and
Further goals for FT-Bh
were improvements in the recovery of thermal energy and a 50 per
cent reduction in electricity consumption. The cabin uses thermally
efficient components and the air conditioning focuses only on parts
of the car where people are sitting.
The amount of electricity used by the LED headlamps, interior
lighting and other electrical components has been drastically
reduced, to the extent that power consumption is half that of
conventional cars. The glazing has been designed for maximum thermal
efficiency and even the matte paint has been chosen for its
excellent heat insulation characteristics.