September 12, 2007 Now here’s an idea that might well catch on – personal transport integrated within a larger vehicle, all of it cost-efficient and environmentally friendly. GM’s Flextreme carries two Segways below the cargo floor, allowing a further 38 km of electric mobility and completing the city commute or extending mobility into environments where cars cannot go. The MPV concept uses a development of GM’s E-Flex architecture, first seen on the Chevrolet Volt Concept but couples it with a 1.3-litre turbo diesel for an all-electric range of 55km - well within the needs of most daily commuters, then the CDTi engine charges the batteries on the fly, extending the operating range. Once docked, the batteries of the Segways can be charged along with the Flextreme’s batteries but that’s only a small part of the concept – innovative accessibility, a reconfigurable dashboard, intelligent use of advanced materials … we like this one!
The Flextreme’s drivetrain is a good indication of what low-emission mobility could look like in the mid-term. As the name suggests
The Flextreme is more than just a demonstration of GM’s latest environmental technology. The monocab body uses lightweight polycarbon panels, and new loading systems including patented Flexload® and Flexdoors®, mixed with the latest advanced materials inside the cabin.
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.
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.
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, communi-cation/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 further 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.
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.
General Motors has already unveiled two further E-Flex variants this year:
• At the Detroit Motor Show in January 2007, the Chevrolet Volt debuted with a 1.0-liter three-cylinder turbo gasoline engine designed to operate on gasoline or E85, a mixture of 85 percent ethanol and 15 percent gasoline.
• At the Shanghai Motor Show in April 2007, GM presented the Chevrolet Volt with enhanced hydrogen fuel cell propulsion. With four kilograms of hydrogen on board, the fuel-cell powered Volt has a range of up to 480 kilometers.
