General Motors Unveils Opel Flextreme Diesel-Electric Hybrid

General Motors is aggressively rolling out variations on its E-Flex theme. In January, General Motors rocked the automotive world with the radical Volt concept car at the North American International Auto Show in Detroit. In April at the Shanghai Motor Show, GM showed a fuel cell-charged version of the Volt. Now, the General has provided an encore at the recent Frankfort Auto Show by showing a variant adapted to the European market. Here, the gasoline engine used to regenerate the U.S. Volt's battery pack was replaced with a thrifty 1.3-liter turbo diesel engine.

E-Flex architecture uses electric drive to propel a vehicle with the ability to plug into the grid to recharge its batteries, plus a flexible choice of ways to provide electricity once away from the outlet. It's a plug-in, but rather than combining an internal combustion powertrain and electric drive to move a vehicle as traditional gas-electric hybrids do, E-Flex is driven strictly by electricity. The internal combustion engine — whether fueled by gasoline, E85 ethanol, or diesel — is used exclusively to power a generator that produces electricity for electric drive. Because of this the engine can be considerably smaller than would be needed otherwise and also run at a more efficient constant speed.

Clean diesel is well established and accepted in Europe, so it makes perfect sense for General Motors to use its European Opel brand to further illustrate the adaptability of the E-Flex architecture by incorporating a diesel-electric hybrid. In this application, the electric propulsion system delivers 120 kW of peak output and 322 Nm of peak torque. Opel's 1.3-liter CDTI turbo diesel is employed only when needed to recharge the lithium-ion battery pack to power the electric motor. This advanced technology diesel uses a pressure-based closed loop technology in the cylinders to control the combustion process. Utilizing the European ECE R101 test procedure for range extender vehicles, the Flextreme is expected to emit less than 40 grams of CO2 per kilometer.

On shorter trips, the Flextreme is able to operate as a zero-emissions vehicle traveling up to 55 kilometers, or 34 miles, before the battery relies on the diesel for recharge. That range is sufficient for many commuters' daily round trip and certainly enough for local errands without the need for internal combustion. Plugging in takes just three hours to fully charge the battery at 220 volts.

The Opel Flextreme is a stunning styling exercise that incorporates design cues from the Opel GTC Coupe unveiled at the Geneva Auto Show earlier this year. While the Volt is a sedan, Flextreme offers the profile of a very aerodynamic crossover vehicle with a decidedly European flair. The design team optimized vehicle weight and aerodynamics by utilizing advanced materials and simulation technology. Flextreme is a highly sculpted form that looks as though it was crafted from a solid billet.

At the leading edge, the Opel cheats the wind with a low-drag profile and exceptionally smooth surfaces. The base of the windshield, for example, has been pushed far forward to create a smooth transition from the hood line. Windshield glass arches back over the driver and passenger seats to form a large greenhouse over the interior. Rather than opting for solid glass, Opel designers divided the glass roof with a center spine that adds both a distinctive appearance and body structure.

Boomerang-shaped headlamps are a signature design element. Each high-tech headlamp unit incorporates crossbeams, fog lamps, and brake cooling intake ducts. The sole engine cooling inlet is a narrow horizontal grille area below the nose. Using a small and highly-efficient diesel running at a low rpm range minimized the need for frontal radiator area.

The Flextreme delivers a very aggressive stance. Hunkered down on 195/45R21 low-profile tires mounted on huge 21-inch five spoke alloy wheels, the Opel appears assertive and confident. Sizeable wheel arches and a pronounced shoulder line over the rear wheels give Flextreme a muscular look.

Flextreme's transformer-like door configuration is quite dramatic. Side doors open to allow unobstructed access to the interior thanks to a rear hinged rear door and noticeably absent center door post. Rear cargo access is even more extreme. The rear hatch is split and opens in a gull-wing fashion to each side. This design allows rear cargo access when the vehicle is parked bumper-to-bumper with another car or other obstruction. With all six doors open, Flextreme looks as though it's ready for liftoff.

Below the rear cargo floor is an innovative underfloor luggage compartment that holds a pair of Segway Personal Transporters. The below-deck Segway "garage" is part of Flexload, a structure that provides versatile cargo handling. Loading and unloading the Segways or other cargo is a snap thanks to a platform that extends and retracts electrically.

Opel utilized honeycomb structures for their lightweight and high rigidity throughout Flextreme's interior. The seats are secured on a mono track for improved floor space. Complementing the large expanse of glass above, Opel designers added a full-width panoramic widescreen display to the dashboard just below the base of the windshield. Display fields are configurable and allow the driver to view images from the two side cameras and front- and rear-facing cameras, in addition to the vehicle information screens.

Another display in the center console offers touch-screen operation and can be programmed with one-touch buttons for presets or multifunction tasks like computer shortcuts. The driving experience is designed to be futuristic in many respects. Below the center touch-screen display is another touch screen for gear selection. Drive, reverse, and park are initiated by touching the corresponding area of the screen.

General Motors is delivering on the electric drive promise made when the E-Flex platform was initially announced in Detroit. The trio of concepts shown thus far certainly show great potential. Let's hope they can keep the momentum and technology moving forward toward production.