Chevrolet VOLT - MONDIAL DE L'AUTO 2008
CHEVROLET VOLT LEADS GENERAL MOTORS INTO ITS SECOND CENTURY <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
DETROIT General Motors launched its next 100 years today by unveiling the much-anticipated production version of the Chevrolet Volt a vehicle that delivers up to 40 miles of gasoline- and emissions-free electric driving, with the extended-range capability of hundreds of additional miles. <o:p></o:p>
Revealing the production version of the Chevy Volt is a great way to open our second century, said Rick Wagoner, GM Chairman and CEO. The Volt is symbolic of GMs strong commitment to the future just the kind of technology innovation that our industry needs to respond to todays and tomorrows energy and environmental challenges. <o:p></o:p>
Form follows function<o:p></o:p>
The design of the Chevrolet Volt production car has evolved from the original concept that was unveiled at the 2007 North American International Auto Show in Detroit. <o:p></o:p>
Because aerodynamics plays a key role in maximizing driving range, GM designers created an aerodynamically efficient design for the production vehicle. Many of the design cues from the concept vehicle endure in the production Volt, including the closed front grille, athletic stance, rear design graphics, outside rearview mirrors and more. The Volts rounded and flush front fascia, tapered corners and grille are functional, enabling air to move easily around the car. In the rear, sharp edges and a carefully designed spoiler allow the air to flow off and away quickly. An aggressive rake on the windshield and back glass help reduce turbulence and drag.<o:p></o:p>
Working closely with GM aerodynamicists to shape the Volt, design and engineering teams developed one of the most aerodynamic vehicles in GMs history. They spent hundreds of hours with the Volt in GMs wind tunnel, testing and re-testing parts such as the front and rear quarter panels, rear spoiler, rockers and side mirrors. Aerodynamic improvements enabled GM to reach the Volts target of driving up to 40 miles (based on EPA city cycle) without using gasoline or producing emissions.<o:p></o:p>
Inside, the Volt offers the space, comfort, convenience and safety features that customers expect in a four-passenger sedan, and it delivers them in a variety of interior color, lighting and trim options unlike any offered before on a Chevrolet sedan. Modern controls and attractive materials, two informational displays, and a touch-sensitive infotainment center with integrated shifter distinguish the Volts interior from other vehicles in the market.<o:p></o:p>
Some of Volts interior technological features include:<o:p></o:p>
- Driver-configurable, liquid crystal instrument display <o:p></o:p>
- Standard seven-inch touch screen vehicle information display <o:p></o:p>
- Touch screen-style climate and infotainment controls<o:p></o:p>
- Optional navigation system with onboard hard drive for maps and music storage<o:p></o:p>
- Standard Bluetooth for cellular phone and USB/Bluetooth for music streaming <o:p></o:p>
New era in automotive transportation<o:p></o:p>
The Chevrolet Volt is leading a new era of electrification of the automobile by creating a new class of vehicle known as the Extended-Range Electric Vehicle, or E-REV. <o:p></o:p>
The Volt uses electricity to move the wheels at all times and speeds. For trips up to 40 miles, the Volt is powered only by electricity stored in its 16-kWh, lithium-ion battery. When the batterys energy is depleted, a gasoline/E85-powered engine generator seamlessly provides electricity to power the Volts electric drive unit while simultaneously sustaining the charge of the battery. This mode of operation extends the range of the Volt for several hundred additional miles, until the vehicles battery can be charged. Unlike a conventional battery-electric vehicle, the Volt eliminates range anxiety, giving the confidence and peace of mind that the driver will not be stranded by a depleted battery.<o:p></o:p>
The Chevrolet Volt can be plugged either into a standard household 120v outlet or use 240v for charging. The vehicles intelligent charging technology enables the Volts battery to be charged in less than three hours on a 240v outlet or about eight hours on a 120v outlet. Charge times are reduced if the battery has not been fully depleted. At a cost of about 80 cents per day (10 cents per kWh) for a full charge that will deliver up to 40 miles of electric driving, GM estimates that the Volt will be less expensive to recharge than purchasing a cup of your favorite coffee. Charging the Volt about once daily will consume less electric energy annually than the average homes refrigerator and freezer units.<o:p></o:p>
Charge out of driving<o:p></o:p>
The Chevrolet Volt offers spirited driving performance in a remarkably quiet interior. More than 220 lithium-ion cells contained within the Volts battery pack provide ample power. The Volts electric drive unit delivers the equivalent of 150 horsepower, 273 lb-ft. (370 Nm) of instant torque, and a top speed of 100 miles per hour. The lack of engine noise, combined with special sound-deadening materials, make the Chevrolet Volt an extremely quiet vehicle to drive.<o:p></o:p>
GM estimates that the Volt will cost about two cents per mile to drive while under battery power compared to 12 cents per mile using gasoline priced at $3.60 per gallon. For an average driver who drives 40 miles per day (or 15,000 miles per year), this amounts to a cost savings of $1,500 annually. Using peak electric rates, GM estimates that an electrically driven mile in a Chevy Volt will be about one-sixth of the cost of a conventional gasoline-powered vehicle. The cost savings are even greater when charging during off-peak hours, when electric rates are cheaper.<o:p></o:p>
CHEVROLET VOLT DEVELOPMENT CHARGES ON
Battery engineers develop new computer testing procedure, leverage global resources to accelerate development of extended-range electric vehicles (E-REV)
Engineers integrate T-shaped battery into vehicle structure
Designers improve aerodynamics to lower energy consumption
WARREN, Mich. Engineers at GMs battery test facilities have developed a new computer algorithm to accelerate durability testing of the advanced lithium-ion batteries needed to power the Chevrolet Volt for up to 40 miles (64 km) of electric-only driving.
This advanced computer program duplicates real-life vehicle speed and cargo-carrying conditions, and compresses 10 years of comprehensive battery testing into the Volts brisk development schedule.
The battery cycling equipment is used around the clock in GM test facilities in Warren, Mich. and Mainz-Kastel, Germany. It charges and discharges power from the prototype batteries based on the Volts approximately 40-mile electric-only drive cycle. Results from this test data will help predict the long-term durability of the battery.
Production timing of the Volt is directly related to our ability to predict how this battery will perform over the life of the vehicle. The challenge is predicting 10 years of battery life with just over two years of testing time, said Frank Weber, global vehicle chief engineer, Chevrolet Volt and E-Flex systems. The battery team is able to utilize human and technical resources around the globe to reduce testing time.
Testing the batteries in the laboratory provides a predictable environment to compare technologies under controllable situations. The batteries will soon be integrated into mule, or test, vehicles with other E-Flex system components for on-road tests.
Extensive analysis in our battery labs is an important step in proving this technology. We expect to further validate these batteries when they are integrated into engineering development vehicles, said Weber. The conditions in a vehicle where the battery is exposed to shaking, moisture and rapidly changing temperature conditions are much more extreme than the controlled settings of the lab.
Engineering an electric vehicle with a battery roughly 6 feet long (1.8 m) and weighing more than 375 pounds (170 kg) requires innovation. The T-shaped battery will be located down the center tunnel of the vehicle and under the rear seats. This integration requires the battery to be treated as part of the vehicle structure. Simulation data also indicates that the center placement provides greater protection to the battery.
The battery is more than just an energy carrier; its a structural component that affects many other aspects of the vehicle, said Weber. Its an integral part of the vehicle that interacts with the vehicles thermal and safety systems and chassis components.
Engineering innovations are also required to maximize the Volts 40-mile electric-only range and minimize the use of its range-extending internal combustion engine. To reduce mass, the Volt is being engineered with a relatively small fuel tank. This reduces weight, but still provides a driving range in excess of 400 miles between fill-ups.
Designing the interior
The battery placement created interior design opportunities that led to several creative solutions that improve aerodynamics and overall comfort.
We made a conscious decision to make the Volt a four-passenger vehicle to keep the roof low, an important aerodynamic enabler, said Bob Boniface, design director, E-Flex. As designers, we must be sensitive to the energy efficiency gains that can be achieved by optimizing aerodynamics, whether its occupant packaging or overall styling. This not only contributes to improved fuel economy or extended range, but can produce beautiful exterior body shapes and innovative interiors.
The battery pushed the occupants outboard, or to the sides of the vehicle, so the design team had to get creative with the sections of the roof structure to enable aerodynamics and provide adequate head room. The interior will accommodate a 6-foot 2-inch (99 th percentile) male comfortably in the front and rear seats.
By having the battery in the middle, we were able to move the occupants apart and give them more space, said Tim Greig, interior design manager for the Chevrolet Volt. We also shrink-wrapped the interior, particularly the doors, for comfort and spaciousness. There is no wasted space.
Being an electric vehicle with a battery down the middle presented unique opportunities to our design team, he said. The net result is a very creative and innovative design, appropriate for an electric vehicle.
Aerodynamic drag, or wind resistance, accounts for about 20 percent of the energy consumed by an average vehicle, directly reducing fuel efficiency.
GMs aerodynamics laboratory, located in Warren, is the center of expertise for optimizing airflow. In addition to fuel economy, range, emissions and acceleration are all affected by aerodynamic drag. The cooling of components like brakes is affected by airflow, as is cornering capability, crosswind response, directional stability and on-center handling. GMs aero lab allows for the testing and development of each of these characteristics.
Aerodynamics development begins with a 1/3-scale model where basic shape and major features are defined. The model includes a highly detailed underbody and engine compartment. Radiator and under-hood cooling flow are developed with computational fluid dynamic models. Simultaneously, computation development takes place to determine the aerodynamic drag of design alternatives. Development continues with full-scale models, where shape is refined and optimized for low wind noise. The development process concludes with a vehicle prototype validation of the math-based analysis and physical testing.
After extensive aerodynamic testing of the Volt, the vehicle now has a coefficient of drag that is 30 percent lower than the original concept, said Ed Welburn, GM vice president, Global Design. Its not easy, but it is a necessity.
The ongoing development of the Volt is just one part of GMs commitment to displace petroleum use in the auto industry through a range of propulsion alternatives, including:
Earlier this year, GM launched Project Driveway, the largest market test of fuel cell vehicles in the world, lending 100 Chevrolet Equinox Fuel Cell vehicles to everyday drivers. GM engineers will analyze customer feedback and use it to develop the next generation of fuel cell vehicles.
GM is the leading producer of E85-capable biofuel vehicles, with more than 3 million on U.S. roads today. GM has committed to having 50 percent of annual sales volume E85-capable by 2012.
By the end of 2008, GM is expected to offer more hybrid models (eight) in the United States than any other automaker.
The Saturn Vue Green Line, Saturn Aura Green Line and Chevrolet Malibu Hybrid will feature GMs mild hybrid technology.
GMs two-mode hybrid technology is available in the Chevrolet Tahoe Hybrid and GMC Yukon Hybrid, and will be added later this year to the Cadillac Escalade, Chevrolet Silverado Hybrid and GMC Sierra Hybrid, delivering highly efficient performance and full functionality.
Going into production later this year is the front-wheel-drive Saturn Vue Green Line 2 Mode Hybrid, expected to deliver up to a 50-percent improvement in combined city and highway fuel economy compared with the current non-hybrid Vue XR, based on current federal test procedures.
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