General Motors is paddling frantically after the hybrid ship sailed by Honda and Toyota, but it doesn’t seem to get the big picture. It touts new, greenish offerings at auto shows and in press releases while rushing to roll out increased numbers of gas guzzlers.
An interesting development, though, is showcased in the Opel Astra diesel-electric hybrid concept. Currently planned only for sale in Europe, the Astra hybrid employs technology that GM’s Allison Transmission division already uses in its hybrid buses. That system is also set to be the starting point of a joint venture between GM and DaimlerChrysler, another company left behind when hybrid rapture hit.
GM vice chairman Bob Lutz is a hybrid skeptic, but even he reluctantly admits that his company should have expended more effort early in the hybrid race. "The reason we missed the boat on hybrids is we business-cased it too much," Lutz told the Detroit Free Press, adding that GM should have treated hybrid development as a public relations expense rather than viewing it as a straight loss—something GM has been dealing with plenty, even without adding hybrids’ extra cost into the balance sheet.
Over 360,000 production Astras, with a variety of engines and trim levels, sold in Europe last year. On the outside, the Astra hybrid concept appears identical to the current front-wheel drive, five-passenger, three-door Astra GTC hatchback. It sports an unusual and striking panoramic roof, extending the windscreen in a smooth sweep over the cockpit. The Astra is built on the same platform as the Saturn Ion, so Saturn enthusiasts are watching closely, hoping for a possible replacement.
Inside, the hybrid features a center-dash color display screen where hands-free phone, route planning, and the current propulsion information reside. The tachometer from the production model is replaced in the hybrid by instruments that provide feedback on the hybrid propulsion system—whether traction is coming from the electric motors, the diesel engine, or both. Another gauge displays the level of battery charge from the nickel-metal-hydride battery pack, which is tucked into the spare tire well along with cooling fans.
Fuel Economy, Emissions, and Performance
GM’s group vice president for powertrains, Tom Stephens, claims that the hybrid Astra gets better than 59 mpg, improving about 25% on comparable diesel models. It is equipped with a 125-horsepower, 1.7-liter, four-cylinder, 16-valve, dual overhead cam turbodiesel with maintenance-free particulate filters. A production Astra using the same CDTI diesel engine found in the hybrid goes from 0-100 km/h (0-62 mph) in 12.3 seconds; the hybrid is expected to reach 100 km/h in just under 8 seconds. That kind of acceleration puts the hybrid on par with the production-model Astra’s top-of-the-line 2.0-liter, 200-horsepower ECOTEC gasoline engine.
GM’s Two-mode Full Hybrid: How it Works
The hybrid’s two electric motors, 30 kW and 40 kW, nestle into the space—and the package—of an automatic transmission. An electronic controller determines the car’s propulsion mode, and the motors act on a series of gears to create an infinitely variable drive system. GM has named its two interlinked methods of hybrid propulsion the "input split" and "compound split" modes.
The input split mode is used to launch the vehicle from a stop, to drive at low speeds, and to boost performance and load-towing capability. In this mode, the system can operate with only the engine, only the motor, or any combination of the two. One motor acts as a generator, powering the batteries, while the other provides drive power to move the car. This mode effectively cuts emissions in city driving.
The compound split mode consists of both motors, managed by the control unit, selectively operating in drive or generation modes, depending on the vehicle speed. They also work in conjunction with other engine technologies, like GM’s Displacement on Demand. The electric motors not only regulate power flow, they aid in extending Displacement on Demand beyond what is possible without hybrid assist. The purpose of the second mode is to optimize fuel consumption at higher speeds.
But Will It Sell?
The hybrid Astra’s price is yet to be determined-check back closer to 2007, when it may go into actual production. Currently, diesel-electric hybrids are estimated to add $8,000 onto the price of a comparable gasoline-only passenger car. But with Europe on board the Kyoto greenhouse-gas reduction treaty and Europeans paying up to $5 a gallon for gas, there just might be a market for this car. At least among those with plenty of money, environmental consciousness, and style sense. How about it, Prince Charles?