The highlight of the Opel stand at the Geneva Motor Show this week is clearly the new Flextreme GT/E concept. This second Flextreme-badged concept is the first midsize car to be powered by General Motors' Voltec powertrain as used in the Chevrolet Volt. The GT/E is just a couple of inches shorter than the Insignia/Regal, but Opel claims it matches the 40 mile electric driving range of the Volt/Ampera.
The same 1.4-liter inline-four gasoline fueled range extender is used along with the 16 kilowatt-hour lithium ion battery pack. However, the designers have taken the lessons learned from the Volt program about how aerodynamics can extend the electric driving range and applied them even more aggressively to the new concept.
The mirror-less GT/E has a drag coefficient of just 0.22 – aided in no small part by a reduced frontal area and vertical fins that can extend out of the body work at speeds over 30 mph to effectively extend the tail and control turbulence behind the car. The Volt has been carefully shaped at rear corners to manage this air-flow, but the new Flextreme adds active aerodynamics to take it to the next level.
The concept also aggressively goes after weight savings with extensive use of carbon fiber, although Opel isn't specifying a mass for this one-off concept. What they are specifying is fuel consumption of 147 miles per gallon (U.S.). How they came to this number remains as mysterious as the magical 230 mpg touted last year for the Volt.
Photos by Drew Phillips / Copyright ©2010 Weblogs, Inc.
World Premiere - Geneva Motor Show 2010
o Brand vision: expressive design driven by efficient environmental performance
o Alternative propulsion: shows versatility of Opel's ground-breaking E-REV technology
Geneva/Rüsselsheim. The Flextreme GT/E concept visualizes the qualities that will characterize the re-energized Opel/Vauxhall brand: High emotional appeal, efficient environmental performance and expressive design – engineered with German precision.
In Opel's strategy for achieving more independence from fossil fuels, electricity plays a key role. The 4.7-meter long Flextreme GT/E concept illustrates how extended-range electric vehicle (E-REV) technology can be plugged into large or mid-size vehicles, as well as compact cars such as the upcoming Ampera.
Opel calls this strategy e-mobility unlimited: adapting the highly efficient E-REV drive system – which removes the limitations of battery-only power – to vehicles across all market segments. To enjoy zero CO2 driving emissions Opel-style, the Flextreme GT/E concept shows that size doesn't matter.
The purposeful design also enables the Flextreme GT/E to achieve a projected drag co-efficient of just 0.22, which helps it reach a 200 km/h-plus top speed as well as conserve energy and extend its driving range. Stand-out visual features include a low and wide stance, wing-shaped lights front and rear, a distinctive nose and grille, floating C-pillars and muscular, sculptured bodywork.
"The Flextreme GT/E concept shows the shape of things to come from Opel," says Frank Weber, Vice President, Corporate and Product Planning. "Bold, expressive and highly efficient, it represents the product strategy we will apply to all our future vehicles, large and small, across all market segments."
Exterior design: expressing efficiency with emotion
The low, coupé-like proportions of the Flextreme GT/E explore the potential for evolving Opel's new design language – sculptural artistry meets German precision – within an envelope optimized for aerodynamic efficiency.
The clean, frontal styling features a low hood line and an extended nose section, which is clasped by wing-shaped, signature LED headlamps. These are deeply carved into the front fenders and across the hood line. The new trapezoidal grille execution is slim but bold. The prominent wing-shaped chrome bar carries a large Opel 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 hood, with an Opel signature central crease line, features narrow longitudinal vents on either side to draw air out of the engine compartment. The muscular fenders 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, emphasizing the flowing lines of the side body. The car's dynamic character is further underlined by a fresh expression of Opel's signature blade motif, now a swooping swage line from the base of the C-pillar into the lower front fender.
Access to the cabin is enhanced by the adoption of rear-hinged rear doors, an evolution of the Opel FlexDoors concept from the new generation Meriva monocab. To preserve the clean exterior looks, all door handles are replaced by light sensors. These trigger the doors 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 emphasize 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. Like that of the Insignia Sports Tourer, the tailgate has a wraparound design for improved trunk access. Its deep glass screen is slightly convex to improve airflow.
The translucency of the fixed glass panel in the center 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 expressive 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 optimize airflow management. The 21-inch alloy wheels are relatively narrow, to reduce wind resistance, and fitted with 195/45, low rolling resistance tires. Clear, flush-mounted trim inserts also minimize air turbulence.
The minimal 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 50 km/h, 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 to conventional materials, these offer a 40 percent weight saving which further contributes to reduced energy consumption and an increased driving range.
The efficient concept also includes GM's ground-breaking E-REV drive system, already developed for the Opel Ampera. The Flextreme GT/E shows the versatility of this technology by displaying it in a larger, mid-size vehicle format.
Despite its greater size and a maximum speed of more than 200 kilometers per hour, the Flextreme GT/E is projected to offer performance similar to that of the Ampera: a battery-powered driving range of up to 60 km – with zero CO2 tailpipe emissions – and a total range of more than 500 km. Average fuel consumption is estimated at 1.6 l/100 km, with CO2 emissions of less than 40 g/km.
Unlike a hybrid vehicle, the wheels of the Flextreme GT/E are powered at all times by electricity. For typical journeys up to 60 km, 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 gasoline 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 500 km, until the plug-in battery pack can be recharged or the car is refueled.
The motor in the electric drive unit delivers a substantial 370 Nm of instant torque, giving lively performance and projected zero to 100 km/h acceleration in less than nine seconds.
The Flextreme GT/E concept is a further step in Opel's unfolding strategy for the electrification of the automobile, which includes a wide portfolio of products using battery, extended-range, hybrid and fuel cell technologies.
Opel Flextreme GT/E Concept: Technical Data
Type 5-door coupé, 4-seat upper mid-size concept vehicle
Co-efficient of drag 0.22
Overall length (mm) 4762
Height (mm) 1308
Width (mm) 1871
Wheelbase (mm) 2900
Front track (mm) 1600
Rear track (mm) 1600
Wheel size 21 inch
Tires 195/45 R 21; extra low-rolling resistance
Type Electric drive, front-wheel-drive
Type Advanced lithium-ion (manganese spinel)
Energy 16 kWh
Nominal voltage 350 volts
On-board charger 3.3 kW
100% recharge time (230V outlet) < 3.0 hours
Electric drive unit:
Max. power 120 kW
Torque 370 Nm
Power 53 kW peak output
Engine type 4-cyl. 1.4l gasoline- Fueled combustion engine
Pure electric mode range 60 km
Full range, range extender engaged > 500 km
CO2 emissions, combined cycle (est.) < 40 g/km
0 – 100 km/h acceleration < 9.0 seconds
Maximum speed > 200 km/h