Opel Flextreme: In Depth

By Frank de Leeuw van Weenen
October 8, 2007 3:53 PM
Filed Under: Concept Car, German, Opel

Press Release

Dynamic, Versatile E-Flex-Concept Opel Flextreme Emits less than 40 g/km CO2

Opel’s Flextreme concept car, which made its premiere at the International Motor Show (IAA) in Frankfurt (September 13 – 23, 2007), boasts the body of a dynamic monocab, as well as the completely new environmentally friendly E-Flex electric propulsion concept and a host of innovative details. Flextreme is part of GM’s ongoing commitment to develop vehicles that reduce CO2 emissions and the automobile’s dependency on petroleum. In contrast to conventional vehicles and hybrids, GM’s E-Flex system uses an electric motor, powered by a lithium-ion battery, to propel the Opel Flextreme concept for up to 55 km of electric-drive-only range. A 1.3 turbo-diesel onboard engine generates additional electricity to replenish the battery and extend the vehicle’s driving range fully charged, the Flextreme’s 55-km all-electric driving range is enough for most daily commuters in Europe to travel without using any diesel fuel or emitting any CO2.

The Flextreme takes the new design language debuted in the GTC Coupé at the Geneva Motor Show several steps further. With the rear-hinged back doors (FlexDoor®) that enable comfortable access to the interior, a large transparent roof and two tailgate doors that open from the side and swing upwards (FlexLoad®), the concept car embodies Opel’s tradition of particularly flexible and practical body concepts with attractive designs. This also includes the FlexLoad’s additional underfloor luggage compartment the latest in a series of innovative Opel solutions such as the Zafira’s seating system (Flex7) and the integrated rear carrier system FlexFix found in the Corsa and Antara. And the big surprise is the integration of two high-tech electric personal transporters, ingeniously packaged below the cargo floor. They can be used in areas that cars cannot enter, thereby adding an extra mobility option. The electric scooters provide up to a 38 km (23 miles) of clean mobility.

For the IAA, FlexLoad® carries special cargo in tune with the Flextreme’s electric propulsion: electrically-powered Segway® Personal Transporters (PTs). These high-tech transportation devices (1) have been modified for their mobile garage. With a twist of the handlebar-mounted release, the handlebar telescopically retracts and rotates downwards for easy loading into the Flexload® compartment. Once docked, the batteries of the Segways can be charged along with the Flextreme’s batteries.

Propulsion: Low-emission mobility with E-Flex technology

The Flextreme’s drivetrain is a good indication of what low-emission mobility could look like in the mid-term. It is based on General Motors’ electric vehicle architecture E-Flex and is always electrically powered. The energy source is a lithium-ion battery, and additional energy comes from a 1.3-liter CDTI engine as needed. This engine is not connected to the wheels; it is only on board to charge the batteries when they are empty and no plug-in facility is available, thereby extending the operating range. The concept car’s diesel engine features latest technology that helps to further reduce exhaust and noise emissions. The cylinders’ pressure-based closed loop technology is used to control the combustion process. Based on the current European test cycle for plug-in vehicles, the Flextreme is expected to emit less than 40 g of C02 per km.(according to European test procedure ECE R101 for range extender vehicles).

Plug-in – full capacity after three hours of charging at 220 volts

The E-Flex strategy is based on combining various drivetrain systems in the same vehicle architecture, depending on what energy source is readily available in the driver’s area. The concept has already been presented in two further versions: at the Detroit Motor Show in January 2007, it debuted with a 1.0-liter, three-cylinder turbo gasoline engine designed for operation with gasoline or E85 (a mixture of 85 percent ethanol and 15 percent gasoline). And at the Shanghai Motor Show in April 2007, GM presented the electric concept car with hydrogen fuel cell propulsion.

Exterior design: Dynamic design language in compact monocab form

The Flextreme body’s key characteristics highlight the new elements of Opel design language: more sculpted surfacing molding, clear style elements such as narrow, boomerang-shaped lights and sloping swage line in the side graphics. The 4796 mm long Flextreme was also designed following the motto of technological efficiency: vehicle weight and aerodynamics are optimized by using advanced materials and simulation technology. The result is a wide range of innovative solutions.

The bottom edge of the windshield has been pulled far forward, so the hood with its characteristic crease is very short. The integrated power socket in the cowl panel allows the car to be charged at any mains supply.

A look at the front of the car quickly reveals that the front grill and rims are covered by lightweight transparent trim, which is made from polycarbonate to improve aerodynamics while maintaining visual aesthetics. The same is true for the special light alloy wheels. Their look remains unchanged, yet disruptive air turbulence is avoided.

Like the wheel design, the large boomerang-like curved front light units are visually deceptive. The designers continue a theme which began with the GTC Concept that debuted at the Geneva Motor Show, and take it to a new level. The vertically oriented front lights slice up the front end in an unusual manner. The boomerang shaped high tech LED headlamp unit houses lightweight crossbeam, fog lamps and air intake for brake cooling which are particularly small in comparison to current trends. The optical illusion continues with the tail lights: at first glance, the concept car appears to have none. The curved rear lights are completely integrated into the tailgates and hidden beneath glass.

Just like all the other windows and a large part of the roof, the windshield is made of especially light polycarbonate. The Flextreme’s panoramic windshield provides a light and spacious interior ambience and stretches over most of the roof, which is reinforced by a spine-like composite structure that extends all the way to the rear floor.

Doors: Unconventional and practical

In keeping with the vehicle’s extraordinary features, access to the FlexLoad® luggage compartment is through two butterfly rear tailgate doors that individually swing open upwards along the central axis of the vehicle. The advantage is that the Flextreme’s trunk is accessible from the side when parked tightly against a wall or another vehicle.

Another key Flextreme innovation is the trademarked FlexDoors® driver and passenger doors: while the front doors open in the conventional manner, the rear doors are rear-hinged. And as there is no center roof pillar (B-pillar), opening both doors on one side creates a large opening for easy entry. The large side opening makes it much easier for parents to secure children in seats in the rear than is the case with conventional doors.

Interior: Futuristic and top technology

Honeycomb structures, which are characterized by low weight and high rigidity, are used extensively in the Flextreme’s interior. This functional, geometric structure can be found in the instrument panel’s lower portion, cabin floor, cargo floor and above the center tunnel where the lithium-ion batteries are located.

Innovative lightweight construction is used for the seats which are anchored to the car’s floor by a mono track rather than the usual two, creating more foot space in the rear. The seats have a light and elegant look thanks to refined upholstery, with some parts in fabric/mesh and corners made of especially soft material. The steering wheel hub also houses a high-tech feature: a full-size driver airbag that is packaged with a special vacuum technique that reduces its overall volume to the minimum.

Set directly under the windshield, the large panoramic display (size: 1.20 m x 0.10 m) in the interior is especially eye-catching. The display fields are configurable. They can show a complete all-around view of the car’s surroundings, for example, as instead of exterior mirrors the Flextreme has two side cameras, one front-facing and one rear-view camera. Alternatively the displays can also show information about the car, radio, phone, etc.

One touch is enough

A second display on the center console features touch-screen operation. At the top, the programmable one-touch buttons are designed like computer shortcuts. They provide easy access to various intuitive menus, including air conditioning, communi­cation/infotainment and navigation functions. The buttons can be freely programmed and adapted to new infotainment systems. Slightly further down is the Flextreme’s touch screen drive selector gate with three driving positions: D, P and R (drive, park and reverse). The gears can also be comfortably selected via touch screen control.

A clever storage system at the front and back of the center tunnel offer brand-typical flexibility. Front and rear passengers can stow items such as mobile phones, MP3 players, iPods and PDAs in two drawers. The best part: the electrical devices are recharged in the drawers by induction and Bluetooth-capable systems can transmit their data to the onboard infotainment system.

Electric Driving with E-Flex

General Motors presents the third variant of its electric vehicle architecture E-Flex, the Opel Flextreme. Its energy source is a battery that powers the electric motor. Another energy source on board – such as a hydrogen fuel-cell or combustion engine – provides more power to increase operating range. In the case of the Flextreme, this is a 1.3-liter CDTI diesel engine. Electric propulsion and a combustion engine are used in a manner fundamentally different from that of conventional hybrid propulsion vehicles.

Regardless of the Flextreme’s operating mode, it is always electrically powered. The diesel engine is onboard solely to power the generator and charge the battery, always running in optimum operating range.

The Flextreme can be charged in around three hours via a standard 220 V electrical socket. A fully charged lithium-ion battery gives the concept car a range of around 55 km in purely electric operating mode. When the battery is run down and no electrical socket available, the Flextreme’s common-rail diesel engine operates at constant rpm to provide electricity and recharge it. The journey need not be interrupted or stopped.

A commuter who lives within 50 kilometers from his workplace, and therefore has a round-trip commute of 100 km every day, would need no diesel and therefore emit zero CO2 with the Opel Flextreme. The only requirement is that he charges up his car each evening and during work. But even if the owner forgets to recharge or travels on vacation in the vehicle, the Flextreme remains economical: it emits less than 40 g/km CO2 in combustion mode, thanks to its efficient engine configured for generating electricity. This increases the car’s range.

Diesel engine: With modern, cylinder pressure-based combustion control

The concept car’s diesel engine also features the newest technology to further reduce exhaust and noise emissions. The closed loop technology is used to control the combustion process.

High-speed Piezo sensors integrated in the glow plugs measure the pressure in the cylinder, so the injections can be matched to the actual combustion in real time. The 1.3-liter four-cylinder engine is the second unit from GM to feature this innovative system, after the 2.9-liter V6 engine displayed at the Geneva Motor Show.

E-Flex system: Flexibility for propulsion systems and energy sources

With the General Motors E-Flex concept, different propulsion systems can be fit into one uniform chassis with electric drive. The aim is to support global diversification of the “energy mix” and to establish the electricity power grid as an energy source.

“Our E-Flex strategy is attractive because we can use different propulsion systems in the same vehicle architecture, depending on which energy source is locally available,” said Larry Burns, GM Vice President, Research & Development and Strategic Planning. “E-Flex ensures flexibility on two levels in terms of the propulsion system and the energy sources. We can extract hydrogen or electricity either from a wide range of renewable sources – such as wind, solar, geothermic, hydro or biofuel – or from traditional sources such as natural gas, coal, nuclear power, and even gasoline or diesel.”

General Motors has already unveiled two further E-Flex variants this year:

Overview of propulsion technology technical data:

Description:

Electric propulsion with onboard Range Extender,

recharging via power grid
Battery system:  
Type: Lithium Ion
Energy content: 16 kWh (minimum)
Peak output: 136 kW
Voltage: 320 to 350 V
Time to full charge: 3 to 3.5 hours at 220 V line voltage
Electric propulsion system:  
Electrical peak output: 120 kW
Peak torque 322 Nm
Generator:  
Peak output: 53 kW
Range Extender:  
Type: Four-cylinder turbo-diesel engine
Displacement: 1.3 liters
Rated rpm: 1500 to 1800 rpm
Peak rpm: 3200 rpm
Tank capacity: 26 liters
Charging unit:  
Type: Power plug
Voltage / Amperage: 220 V / 15 A
Range (pure electric propulsion): 55 km

C02 emissions / km

 less than 40 g according to European test procedure ECE R101 for range extender vehicles
   

Efficiency Can Look So Good

Form follows function. Opel has consistently implemented this maxim with the Flextreme using the new design language that debuted with the GTC Concept at the Geneva Motor Show. Key characteristics are the signature design cues, such as narrow, boomerang-shaped lights, the blade feature on the side, as well as much more sculpted surfaces.

“Our job was to combine the E-Flex chassis with a body style that’s dynamic, yet makes the best use of space,” explains Anthony Lo, Head of Advanced Design. “We also wanted to give the current Opel design language a special accent and to update the history of earlier concept cars with a few surprising innovations.” The 4796 millimeter-long Flex­treme was also designed following the technological motto of efficiency: whether it was weight or aerodynamics, ideas were always found to achieve the best benefits.

The result is a wide range of innovative solutions. For example, a close look at the front of the car reveals just how small the air intakes are in comparison to current trends. The cooling-air requirements of the small, economical turbo-diesel engine and electric motor are considerably lower than those of conventionally powered cars. The only air intakes are two openings beneath the bumper. The original idea to completely forego the conventional radiator grille was quickly rejected, however. Anthony Lo: “The polished aluminum bar with the Opel logo is so brand-typical that there was no way we could leave it out in a groundbreaking concept car.”

The brand recognition elements are covered with transparent trim, which contributes to better aerodynamics. A closer look shows that the Opel logo trim is three dimensional. The unusual-size 195/45 R 21 wheels boast a similar feature, and the special alloy rims also have transparent trim. Their look remains unchanged, yet disruptive air turbulence is avoided. Developed by Dunlop especially for this project, the tires have a very special friction-optimized tread design.

Building on the initial collaboration with the Chevrolet Volt, GM Europe Design worked closely with SABIC Innovative Plastics, formerly GE Plastics, to develop the Flextreme, which showcases unique polycarbonate window glazing, lightweight body panels and energy absorbers for increased pedestrian protection. These high-performance thermoplastics allowed designers to reduce glazing and body panel weight by up to 40 percent, resulting in increased fuel reduction.

Lights: Create an optical illusion

Like the wheel design, the large boomerang-like curved front light units are visually deceptive. The designers continue a theme which began in the GTC Concept that debuted at the Geneva Motor Show, and take it to a new level. The vertically oriented front lights slice up the front end in an unusual manner. The boomerang-shaped, high-tech LED headlamp unit houses the lightweight crossbeam, fog lamps and air intake for brake cooling. The optical illusion continues with the tail lights: at first glance, the concept car appears to have none. The curved rear lights are completely integrated into the tailgate doors and hidden beneath glass. If one of the tailgate doors is opened, an additional parking light switches on so that the Flextreme can be easily seen in the dark.

Distinctive characteristic: Power socket on hood

As the bottom edge of the windshield has been pulled far forward, the hood with its characteristic center crease is very short. The prominent feature here is a power socket that allows the electric car’s battery to be charged by an external electricity source. Just like all the other windows and a large part of the roof, the windshield is made of polycarbonate.

Not just for young parents: Unconventional doors

The replacement of the exterior mirrors with small cameras helps the driver maneuver the Flextreme easily, despite its width of 1814 millimeters (see Interior chapter). And it is not only the slightly higher seat position (vehicle height 1760 mm) that makes getting in and out of the Flextreme easier. The concept car also has a special door design – the innovative FlexDoors®. While the front doors operate in the conventional manner, the back doors are rear-hinged. And as there is no center roof pillar (B-pillar), opening both doors on one side creates a large opening for easy entry. This design will be especially appreciated by customers with a taste for practical ideas. The French door style opening makes it much easier for parents to secure children in the rear seats than through conventional, front-hinged doors.

The Flextreme’s transparent roof stretches over the interior in a large U-shape that is open at the rear, giving the sporty monocab a light and spacious ambience. The roof is reinforced by a spine-like composite structure that extends all the way to the rear floor. This center beam is connected to the hidden C-pillars to form a highly rigid structure, giving the body the necessary stability to compensate for the missing B-pillar.

FlexLoad®: Gull wings side-opening double tailgate doors

The unique roof construction also allowed for the tailgate’s unusual design: there are actually two, gull wing tailgate doors that swing open individually to allow access to the trunk from either the right or left side of the vehicle. The advantage is that the Flextreme’s trunk is fully accessible from the side when parked tightly against a wall or another vehicle, or when a bicycle rack is fitted on the rear.

Fully integrated: FlexLoad® offers second luggage compartment behind bumper

The additional underfloor luggage compartment is the Flextreme’s most ingenious feature. The practical-flexible innovation is the result of research into a stowage option for heavy luggage that eliminates the need to lift it up, over and into the trunk. The underfloor storage system extends and retracts electrically. The FlexLoad® system was inspired by the integrated FlexFix® bicycle carrier, which made its premiere in the TRIXX concept car. Opel now offers FlexFix® ex works in the Corsa and Antara models.

Onboard mobility option

For the IAA, FlexLoad® carries special cargo in honor of the Flextreme’s electric propulsion: under the cargo floor, there are two electrically-powered Segway® Personal Transporters (PTs)1. These high-tech transportation devices are equipped with telescoping and retractable handlebars, enabling a perfect fit in their mobile garage. There are also two docking stations integrated in the FlexLoad® compartment, so that the Segway PTs can be charged along with the Flextreme’s batteries.

“With this vehicle, General Motors and Segway are redefining personal transportation and urban mobility. We feel there is an enormous opportunity right now for people everywhere to embrace new transportation options that can help shrink their carbon footprint – and options such as these clean, electrically-driven mobility concepts are a major step in this direction,” says James Norrod, CEO and Chairman of Segway.

One of GM/Opel’s objectives of the E-Flex architecture is to build an electric car that boasts a considerably increased operating range, thanks to its integrated electric generator (see E-Flex chapter). The two Segways provide the Flextreme with a new dimension of mobility: when the destination is reached, such as a car-free zone in a city center, the Flextreme passengers have yet another motorized mobility option. Fully charged, the Segway scooters offer up to 38 kilometers of transportation at the touch of a button.

Lightweight Honeycomb Elements and Informative Panorama Display

The interior of the Opel Flextreme is dominated by elegant silver tones, and the wings of the instrument panel flows into the door trim, enhancing the feel of spaciousness. Different to pure driver-oriented cockpits, passengers here will not feel excluded.

Honeycomb structures, which are characterized by low weight and high rigidity, are used extensively in the Flextreme’s interior. This functional, geometric pattern can be found in the instrument panel’s lower portion, the cabin floor, the cargo floor and above the center tunnel where the lithium-ion batteries are located. The wing-shaped upper part of the instrument panel also has a honeycomb-design grain.

Light and elegant: Seats mounted on monorails

Purely decorative elements such as chrome trim have been dispensed with to save weight. Innovative lightweight construction was used for the seats, which are anchored to the car’s floor by mono tracks rather than the usual two. This enhances foot room for the rear passengers. The seats have a light and elegant look thanks to the refined fabric/mesh upholstery and seat corners made of especially soft material. An unusual detail is the silicon inserts in the floor mats which prevent feet from slipping from the pedals and also reduce noise.

The comparatively thin steering wheel rim with aluminum spokes highlights the Flextreme’s lightweight design philosophy. Despite its small size the steering wheel hub houses a full-size driver airbag. Despite its volume, the airbag has compact installation dimensions as it is not folded up in the conventional way, but with the help of a vacuum to save as much space as possible.

Control center: 180-degree panoramic display

The panorama display in the interior is especially eye-catching. Set directly under the windshield, the large display (size: 1.2 m x 0.1 m) means the driver no longer has to look away from the road to receive information. The three fields on the panorama display are reconfigurable. They can show a complete all-around view of the car’s surroundings, as instead of exterior mirrors the Flextreme has two side cameras, one front-facing and one rear-view camera. The dreaded blind spot, where cyclists or other vehicles can easily be overlooked, no longer exists thanks to this modern technology.

Alternatively, the display fields can also show information about the car or animations. When a telephone call comes in via the integrated GSM phone, a picture of the caller can automatically be shown, enabling the Flextreme driver to decide whether to take the call without having to read the number or name.

Always up-to-date: Programmable touch-screens

A second display on the center console features touch-screen control. At the top, the programmable one touch buttons are designed like computer shortcuts. They provide easy access to various intuitive menus. As infotainment technology evolves during the life span of a vehicle, the user interface can be re-programmed to allow control of new infotainment systems.

Slightly further down is the Flextreme’s touch screen drive selector gate with three driving positions: D, P and R (drive, park and reverse). The gears can also be selected via touch screen control. An electric handbrake replaces the conventional mechanical component and there is no longer an ignition key. Superimposed information such as “system is ready” or “electric handbrake activated” inform the driver of the car’s status.

Two further instruments behind the steering wheel provide the driver with essential vehicle data, including battery charge level and whether the battery is being charged by regenerative braking, i.e. the resulting electrical energy from braking or from overrun.

New color concept: A warm red light fills the interior

Flextreme also features the new instrument lighting concept demonstrated in the Opel GTC Coupé concept car at the Geneva Motor Show in 2007. Instead of the traditional amber tone, a warm, lively red now gives the interior ambience more character and emotional appeal.

Storage: Flexible system for front and rear passengers

The Opel Flextreme’s battery is housed where you would find the center or drivetrain tunnel in conventional vehicles. The rechargeable battery cells are under a dark-tinted cover in honeycomb design. A clever storage system at the front and back of the battery tunnel offers the brand-typical flexibility.

Front and rear passengers can stow items such as mobile phones, MP3 players, iPods and PDAs in two sliding drawers. The best part: the electrical devices are recharged in the drawers by induction and Bluetooth-capable systems can transmit their data to the onboard infotainment system.

Same Driving Fun, Lower Emissions: The Future Has Already Begun

In essence, the environmental strategy of General Motors and Opel is to reduce CO2 emissions in the short term and introduce new propulsion technologies in the long term. The goal is to offer customers vehicles that can operate on many different energy sources. The multi-tiered approach includes accelerating the development of electrically powered vehicles, stepping up efforts to displace fossil fuels and increasing the efficiency of gasoline and diesel engines.

Electrically powered vehicles: Electric cars, hybrids and fuel-cell models

The Opel Flextreme concept car embodies this vision of versatility. It combines electric propulsion and a combustion engine in a fundamentally different manner than in conventional hybrid propulsion vehicles. Regardless of the Fkextreme’s operating mode, it is always electrically powered. The diesel engine is onboard solely to increase the electric car’s range. When needed, it runs constantly within its optimum operating range, powering a generator that charges the battery. Flextreme passengers can also travel electrically and environmentally compatibly over short distances in cities, as two Segway Personal Transporters(1) are always onboard and easy to load and unload.

Like the Chevrolet Volt, the Opel Flextreme is based on the E-Flex electric vehicle architecture and both feature increased operating range. Under the category of full hybrids, GM’s portfolio also includes the “Two-Mode” hybrid system, which was developed jointly with BMW and DaimlerChrysler and made its US production premiere in the large Chevy Tahoe and GMC Yukon SUVs in 2007.

The “Two-Mode” system is unique in its compactness and adaptability to various vehicle sizes and driving conditions. Its integrated electric propulsion operates autonomously over short distances, but also contributes to covering the powertrain’s performance peaks. This allows for a more efficient layout of the combustion engine, which includes Active Cylinder Control (ACC). GM will bring 12 hybrid models with this concept on to the market, offering its customers a variety of options to minimize fuel consumption in different price and vehicle classes.

The Opel Corsa Hybrid Concept, which will also make its world premiere at the IAA 2007, is in contrast a mild hybrid. The belt-driven starter-generator combines the functions of starter and generator, and thanks to the automatic stop/start system, helps save fuel by immediately switching off the combustion engine when the car stops. The starter-generator only restarts the combustion engine when the brake is released. On the road, the electric unit provides additional torque for improved driving performance, for example by boosting the combustion engine when starting up from a standstill or accelerating.

In North America, General Motors also offers a mild hybrid in which the electric propulsion helps increase the performance and efficiency of the combustion engine. The Saturn Vue Green Line hybrid system reduces fuel consumption in a number of ways, including: switching off the engine at every stop, immediately switching it on again as soon as the brake pedal is released, early fuel supply cut-off during overrun, recouping kinetic energy when braking and charging the battery during driving conditions during which this is particularly efficient.

At the IAA, GM will also unveil the next generation of hydrogen-powered fuel cell vehicles with the HydroGen4. The fuel cells utilize an electro-chemical process between hydrogen and oxygen to produce electrical energy – and water as a by-product – and power the HydroGen4’s electric motor.

Alternative fuels: Ethanol and natural gas models advancing

In the mid-term, GM wants to offer an increasing number of models that run on alternative fuels. In Europe, the Swedish brand Saab is very successful in its pioneering role with its BioPower technology. The Cadillac will also tap into this success when it launches its BLS model with bioethanol propulsion this fall. Bioethanol variants will be available for Opel/Vauxhall and Chevrolet brands from 2010.

Natural gas is a further highly efficient alternative fuel. Opel currently offers two models ex works with this especially environmentally friendly and economical form of propulsion: the Zafira CNG and Combo CNG (Compressed Natural Gas) consume just 5.0/4.9 kg of natural gas per 100 km (corresponding to 138/133 g CO2/km respectively). The seven-seat Zafira CNG emits just under 20 g CO2 per kilometer and seat. Both can also operate on biogas.

Consumption-optimized combustion engines: ecoFLEX initiative from Opel

Opel’s environmental strategy includes the introduction of low-emission ecoFLEX models in every Opel/Vauxhall model line. These gasoline and diesel cars combine economy and driving fun with low fuel consumption and lower CO2 emissions in every vehicle class. The premiere ecoFLEX Opel/Vauxhall model is a Corsa 1.3 CDTI that produces just 119 g/CO2 per kilometer. The Corsa ecoFLEX will debut at the IAA 2007 and enter the market in early 2008.

Extremely Flexible – A Short Story About Versatility

Innovative body solutions from the inventor of the European station wagon

The history of automobile flexibility at Opel started with the station wagon: in 1953 the Rüsselsheim automaker introduced the first station wagon to the market and coined the generic term CarAVan. More than 50 years later, Opel is still trendsetter with elegant and practical station wagons, a synthesis of chic sedan and spacious commercial vehicle. The concept was described in an Opel brochure over 50 years ago: “With just a few turns and minimal effort, the rear seats are folded down – the elegant people carrier Opel station wagon turns into a utility vehicle with high service value and real economy.”

A major further development of the station wagon concept was made with the compact vans Zafira (1998) and Meriva (2001). Thanks to their monospace body, they offer not only optimum use of space, but also impressive versatility. While owners of conventional vans always have to decide before they drive off if they need room for a lot of luggage or lots of seats, the Flex7 system in the best-selling Opel Zafira solves this dilemma: all seven seats are always on board. The two single seats in the third row can be folded down into the car floor as needed, and the center bench seat can be folded down and slid forward.

The Meriva is configured a bit differently. Maximum flexibility is built into the second row of seats, which can be turned into two separate seats with maximum leg and elbow room, into a three-seat bench seat or, for maximum luggage space, simply be folded down. In 2001, the Opel top model Signum showed that a van body is not absolutely necessary for such versatility. Like in the Meriva, the individual rear seats can be slid longitudinally and the seat backs can be tilted. A third seat can also be folded out when needed. The separate seats are easily and quickly folded down to create a station wagon-like load area. The flexible configuration of the rear seats allows for varying luggage compartment volume as needed.

The Tigra TwinTop and Astra TwinTop interpret body flexibility very differently: both are a coupé and cabrio in one. They feature a retractable steel roof that disappears into the luggage compartment at the touch of a button. To maintain the trunk’s roominess, the four-seat Astra TwinTop is designed with a three-part roof that folds together in a very space-saving manner.

The rear carrier system Flex-Fix offered in the Corsa and Antara takes luggage flexibility even further. Like a drawer, it can be pulled out of the rear bumper and can carry two bicycles or a large box for additional luggage. The Opel principle also applies to Flex-Fix – no tools are needed, nothing has to be built in or taken out.

Opel engineers have also shown their creativity in details. The new Corsa comes standard with a dual luggage compartment floor. It can be fixed in various horizontal positions, depending on load capacity needs. If it is not needed at all, it can be tucked away in a holder on the rear bench seat back.

The Flex-Organizer system enables neat organization of the large luggage spaces in the Astra and Vectra station wagons as well as in the Antara. All kinds of transport containers and nets can be hooked into its aluminum rails, so even smaller or fragile cargo is always safely stowed away. Of course all Opel station wagons and vans come with an easy-to-install luggage net that separates and protects the passengers from the luggage compartment. In all models, it can be easily installed behind the rear seats, or in maximum loading space configuration, behind the front seats.

A completely different kind of flexibility in many Opel models comes with the TwinAudio system. It allows passengers in the rear and front seats to listen to different entertainment programs, thanks to two headset sockets in the center rear console and a car radio that can simultaneously play two stations or a CD and a radio station.

Environmentally Compatible Mobility Concepts

Since 1971, designers and engineers at GM/Opel have been researching cars for the future

The current Flextreme concept car is the latest step in an electric propulsion research program that began in 1971, when Georg von Opel – grandson of founder Adam Opel – piloted a very special Opel GT around the Hockenheim racetrack at a top speed of 188 km/h. Two coupled direct-current engines produced a joint output of 90 kW, and power was provided by 280 cells in a 590 kg nickel-cadmium battery. At a constant speed of 100 km/h, the car had a range of 44 kilometers.

The following is a chronological overview of research and concept cars engineered by Opel for maximum environmental friendliness:

1981 – Opel TECH 1

Opel caused a stir at the IAA in 1981 with the TECH 1 research car. With a face that anticipated the Omega generation to be presented in 1986, the TECH 1 had a drag co-efficient of just 0.235 – a top aerodynamic value for the time. The “four-door coupé with tailgate” was based on the Kadett D, and had flush-fitted windows, a fastback with separation edge and underbody shield for extraordinary aerodynamics. The interior was also groundbreaking: electronic digital instruments only displayed absolutely necessary information and electronic touch keys controlled all functions except braking, acceleration and the clutch.

1990 – Opel Impuls 1

The Impuls 1 was based on the Kadett and was jointly developed by RWE Energie AG and the battery manufacturer SAFT. It was powered by a 16 kW direct-current shunt engine, while nickel-cadmium cells with liquid electrolyte were used in the batteries. It had a range of around 80 km and a top speed of 100 km/h.

1991 – Opel Impuls 2

Opel Advanced Development engineers designed a pre-production electric vehicle for four passengers based on the Astra station wagon for the 1991 IAA. Called Impuls 2, the Opel prototype featured propulsion technology from the electric sports car Impact that General Motors presented in spring 1990. In total, 32 lead-acid batteries delivered power to two three-phase asynchronous motors with a joint output of 85 kW/115 hp.

1991 – Opel Eco 2

With a Euromix consumption of five liters per 100 km, the Opel Eco 2 required around 27 percent less fuel than a comparable production engine of that time. The research vehicle featured a 1.6-liter gasoline engine that generated 50 kW/68 hp and an automatic clutch with a Start/Stop function, which automatically shut off the warm engine at stops – for example at traffic lights. Special characteristics of the concept car included the engine modifications as well as improved aerodynamics and special tires with reduced rolling resistance.

1992 – Opel Twin

Highlights of the much acclaimed Twin concept car included interchangeable drive units, with the engine, transmission, rear axle and energy accumulator housed inside. The vehicle thus ran on whichever drive assembly was most environmentally compatible and economical in any given situation. For instance, a three-cylinder gasoline engine (0.8 liter, 34 hp) was used for highway driving while an electric unit with two wheel-hub motors (each with 14 hp) came into play for city and short-distance driving. The drive train was located in the rear, allowing an unusual seating layout: instead of sitting front left, the driver had a central single-seat position, with three passenger seats in the back.

1993 – Opel Astra Impuls 3

The Impuls 3 was based on the Astra station wagon and was just as practical as the production vehicle with a combustion engine. It offered space for five passengers, had a big, versatile luggage compartment and a high payload. From 1993 to 1997, Opel entered ten Impuls 3 models in a large-scale electric car test on the island of Rügen, with the vehicles covering a total of more than 350,000 kilometers. Five electric Astras were fitted with nickel-cadmium batteries and the other five with sodium/nickel-chloride high-energy batteries. The three-phase asynchronous engine developed 45/42 kW.

1995 – Opel Corsa Eco 3 concept

The Opel Corsa Eco 3, the world’s first drivable “three-liter” car, made its debut at the 1995 IAA in Frankfurt. One year later, the prototype achieved an average consumption of 2.69 liters diesel per 100 km during the ECO Tour of Europe. Intelligent lightweight construction contributed to its record-setting fuel efficiency: hood, doors and fenders were made of composite materials reinforced with carbon fiber, and the chassis components were aluminum.

1995 – Opel Combo Plus

In late 1995, Opel presented a pre-production proposal for an environmentally compatible city logistics concept car. Two sodium/nickel-chloride high-energy batteries operated in combination with a 45 kW three-phase asynchronous engine to provide noiseless propulsion in the Combo Plus. The special innovation in this electric vehicle concept: the batteries mounted under the car floor could be changed in ten minutes, providing a further 200 kilometers of operating range.

1996 – General Motors EV1

Strictly speaking, the EV1 was not a concept car, as 1,117 units of the electric coupé were produced, 800 of which were delivered to customers in California and Arizona under a leasing agreement. The EV1 was based on the “Impuls” concept car and propelled by a three-phase alternating current induction engine. Thanks to its light aluminum design and details like ultra-light magnesium wheels, extremely low air resistance of cd=0.19 and energy recuperation from braking, the EV1 had a respectable range of up to 240 km. Two different batteries were used, each with 26 accumulators. The first battery pack consisted of 12-volt lead-acid accumulators producing 18.7 kWh of energy, later 13.2-volt nickel-metal hydride accumulators with 26.4 kWh energy content were used.

1999 – Opel G90 concept

First presented at the IAA in Frankfurt in 1999, the low-emission G90 Opel concept car weighed just 750 kg. The G90 name given to the spacious four-seater in the Astra category had special significance: the concept vehicle – powered by a 44 kW/60 hp three-cylinder gasoline engine with a load controlled intake-port shutoff – had a CO2 emission figure of just 90 g per kilometer. This corresponded to an MVEG standard consumption of 3.88 liters per 100 kilometers.

This outstanding fuel efficiency was achieved by consistent lightweight design and an extremely low cd value for a vehicle of this size, 0.22. At the same time, the G90 – whose body lines provided a hint at future Opel vehicle design language – broke new ground in interior design.

2002 – Opel Eco Speedster Concept

The aerodynamic and low-weight Eco Speedster prototype with its spectacular fastback body impressively demonstrated the performance of the 1.3 CDTI ECOTEC engine. With an output of 82 kW/112 hp, the concept car reached a top speed of over 250 km/h during initial tests, yet consumed only 2.5 liters of diesel per 100 km (MVEG cycle). Based on the mid-engine Speedster sports car, the two-seat concept car displayed in Paris carried on the tradition of the 1972 world record-setting Opel GT. It had a carbon fiber body with considerably improved aerodynamics (Cd = 0.20) and weighed only around 660 kg.

2005 – Opel Astra Diesel Hybrid concept

The Opel Astra Diesel Hybrid offered fuel consumption reductions of up to 25 percent with even more driving fun. The concept car was powered by a 92 kW/125 hp 1.7 CDTI engine with a maintenance-free particulate filter, as well as two electric motors with outputs of 30 and 40 kilowatts. Depending on the driving conditions, the electric motors delivered additional power for the diesel engine or propelled the Astra on electric power alone. A sophisticated engine control module determined the mode, which was then realized by the hybrid transmission. The electric motors’ boost function provided excellent driving performance: acceleration from zero to 100 km/h took less than eight seconds. And with an MVEG combined consumption of less than four liters, the concept car was very sparing with fuel.