The Vauxhall Flextreme GT/E is a new concept that will be unveiled at the Geneva Motor Show today.
Measuring 4.7 meters in length the Vauxhall Flextreme GT/E an electric vehicle that features a drag coefficient of only 0.22 and can reach a top speed of 125 mph.
Fitted with the E-REV drive system already implemented in the Vauxhall Ampera, the Vauxhall Flextreme GT/E is able to cover 40 miles with just power coming from its batteries while total range is extended to 300 miles when the small petrol engine also being used.
Average fuel consumption for the Vauxhall Flextreme GT/E is 175 mpg with CO2 emissions of less than 40 g/Km. 
Vauxhall press release :
Geneva/Luton – These are the first official images of
Vauxhall’s stunning Flextreme GT/E concept car, which will be revealed
at the Geneva Motor Show today.
In Vauxhall’s commitment to achieving power without the need for
fossil fuels, electricity plays a key role, and the 4.7-metre long
Flextreme GT/E concept illustrates how extended-range electric vehicle
(E-REV) technology can be plugged into large or mid-sized vehicles, as
well as compact cars, like the upcoming Ampera.
Vauxhall calls its strategy ‘e-mobility unlimited’,
which will effectively adapt the highly efficient E-REV drive system –
which removes the limitations of battery-only power – to vehicles
across all market segments. In other words, the Flextreme GT/E concept
shows that size really doesn’t matter when it comes to driving a car
with zero CO2emissions.
Sleek and aerodynamic, the Flextreme GT/E achieves a projected drag
co-efficient of just 0.22, allowing it to reach an estimated top speed
of 125mph-plus while conserving energy and extending the driving range.
Stand-out visual features include a low, wide stance, wing-shaped
lights front and rear, a distinctive nose and grille, ‘floating’
C-pillars and muscular, sculptured bodywork.
Exterior design
The clean frontal styling features a low bonnet line and an extended
nose section, which is clasped by wing-shaped, signature LED headlamps,
which are in turn carved into the front wings and across the bonnet
line. The new trapezoidal grille is slim but bold, with the prominent
wing-shaped chrome bar carrying a large Vauxhall emblem, which doubles
as a socket for charging the Flextreme GT/E’s battery pack.
The upper section of the grille is used to admit cooling air, the
lower portion being covered by a translucent panel. The absence of
additional air intakes allows a low frontal area for aerodynamic
efficiency and also enables the Flextreme GT/E to meet future
pedestrian protection requirements.
The sculpted bonnet, with a Vauxhall-signature central crease line,
features narrow longitudinal vents on either side to draw air out of
the engine compartment. The muscular wings and wheel-arches sweep back
into the side-body.
In profile, the Flextreme GT/E is distinguished by innovative,
stubbed C-pillars. This floating design allows the glasshouse to be
extended rearwards under the arching roofline, emphasising the flowing
lines of the side-body. Vauxhall’s signature blade motif is
reinterpreted in a swooping swage line from the base of the C-pillar
into the lower front wing.
Access to the cabin is enhanced by the adoption of rear-hinged rear
doors, an evolution of the FlexDoors concept from the new generation
Meriva. To preserve the clean exterior looks, all door handles are
replaced by light sensors. These trigger the doors to open when covered
by the driver’s or passenger’s hand. To reduce air turbulence, exterior
front door mirrors are also absent, replaced by small camera pods in
the base of the A-pillars.
At the rear, a strong shoulder line embraces sculpted wheel-arches
that further emphasise the Flextreme GT/E’s wide, ground-hugging
stance. The coupé look is completed by a steeply raked tailgate,
carrying wing-shaped LED light units which echo the form of the front
headlamps. And taking a leaf from the Insignia Sports Tourer’s book,
the tailgate has a wraparound design for improved boot access, enhanced
by a convex deep glass screen to improve airflow.
The transparency of the fixed glass panel in the centre of the roof
is adaptive, allowing sunlight to warm the interior in the cold of
winter, but darkening for coolness in summer. A duct at the rear edge
of the roof is for additional cooling of the battery and electronic
components.
Managing airflow and saving weight
Integral to the Flextreme GT/E’s dramatic looks is the efficiency of
the design execution. The small frontal area, low roof height (1308 mm)
and a flat, enclosed underbody all enable the car to cleave the air
with a minimum of disturbance.
A series of measures optimise airflow management. The 21-inch alloy
wheels are relatively narrow, to reduce wind resistance, and are fitted
with 195/45, low rolling resistance tyres. Clear, flush-mounted trim
inserts also minimise air turbulence. 
The small front intake improves airflow around the nose of the car
and the underbody sweeps up, venturi-like, at the rear to further
reduce drag.
The Flextreme GT/E also explores the potential for active shape
shifting.  At speeds above 30mph, a vertical panel extends along the
body from the air extraction slot behind each rear wheel-arch. These
350 mm-long side spoilers guide high-speed airflow around the rear
corners of the car, further reducing the amount of turbulence.
Mass reduction measures for the body include the use of lightweight,
carbon composite outer panels, polycarbonate window glazing and
aluminum alloy structural components. Compared with conventional
materials, these offer a 40 per cent weight saving which further
contributes to reduced energy consumption and an increased driving
range.
Powertrain
The Flextreme GT/E concept also includes the groundbreaking E-REV
drive system, already developed for the Vauxhall Ampera.Despite its
greater size and a maximum speed of more than 125mph, the Flextreme
GT/E is estimated to offer performance similar to that of the Ampera: a
battery-powered driving range of up to 40 miles – with zero CO2tailpipe emissions – and a total range of over 300 miles.  Average fuel consumption is estimated at 175mpg, with CO2emissions of less than 40g/km.
Unlike a hybrid vehicle, the wheels of the Flextreme GT/E are
powered at all times by electricity. For typical journeys up to 40
miles, energy is supplied by a T-shaped lithium-ion battery pack
located under the floor and rear seat.
However, unlike a battery-only electric vehicle, the Flextreme GT/E
eliminates any possibility of range anxiety through fear of being
stranded without power. The small petrol engine/generator is seamlessly
engaged to provide electricity whenever the battery’s supply becomes
depleted. In this mode, the driving range is extended to more than 300
miles, until the plug-in battery pack can be recharged or the car is
refueled.
The motor in the electric drive unit delivers a substantial 370Nm of
instant torque, giving lively performance and projected zero to 62mph
acceleration in less than nine seconds.
The Flextreme GT/E concept is a logical next step towards Vauxhall’s
emerging strategy for the electrification of the car, which will in
time include products using battery, extended-range, hybrid and fuel
cell technologies.

Source: Vauxhall