While Volvo and Toyota showcased their prototype plug-in cars, Saturn announced at the North American International Auto Show last week that production may begin as soon as 2010 on a plug-in hybrid electric version of the Saturn Vue Green Line, expected to be the first regular production plug-in hybrid electric vehicle.

Depending on a consumer’s drive cycle, the Vue plug-in hybrid will be the most fuel-efficient vehicle offered by a major automaker.

This Vue Green Line will use a modified version of GM’s two-mode hybrid system and plug-in technology, a lithium-ion battery pack, highly efficient electronics and powerful electric motors to achieve significant increases in fuel economy.

When the lithium-ion batteries are fully charged, the Vue plug-in hybrid will potentially double the fuel efficiency of any current SUV. After electric-only propulsion depletes the lithium-ion energy storage system to a specified level, the battery is replenished by utilizing the two-mode hybrid system’s electric motors and regenerative brake systems.

“We announced late in 2006 that a plug-in hybrid electric vehicle was a top priority, and the fact that we’re now announcing production timing to bring the industry’s first plug-in to market, while tackling many technology hurdles along the way, demonstrates our commitment to diversifying from petroleum and reducing emissions,” said Saturn General Manager Jill Lajdziak.

In early testing, the Vue Green Line plug-in hybrid is capable of electric-only propulsion for more than 16 kilometres at low speeds. At higher speeds or when conditions demand it, such as brisk acceleration, a combination of engine and electric power or engine power-only drives the vehicle.

The vehicle’s lithium-ion batteries can be fully recharged in four to five hours by simply connecting the vehicle to any standard 110V household electrical outlet. The connection port on the vehicle will be integrated into the front fender. By recharging rather than refueling, the Vue Green Line plug-in hybrid reduces petroleum consumption.

A plug-in hybrid-electric vehicle differs from a non-plug-in hybrid-electric vehicle by offering extended electric-only propulsion, additional battery capacity and the ability to be recharged from an external electrical outlet.

The two-mode hybrid system to be introduced on the 2009 Saturn Vue Green Line 2 Mode will be altered for use with plug-in technology.

In addition to plug-in capabilities and the modified two-mode hybrid system, the Saturn Vue Green Line hybrid SUV’s powertrain will feature two interior permanent magnet motors within the two-mode transmission and GM’s 3.6L V-6 VVT gasoline engine with direct injection.

The lithium-ion energy storage system will be replenished by utilizing the two-mode hybrid system’s electric motors and regenerative braking systems.

The Saturn Vue Green Line plug-in maintains two driving modes — one for city driving, the other for highway driving — and four fixed mechanical gears to maximize efficiency while maintaining performance.

In addition, special controls will be utilized to enable higher speeds during electric-only propulsion and maintain electric-only propulsion for longer periods of time.

Meanwhile, Volvo unveiled The Volvo ReCharge Concept, a plug-in hybrid with individual electric wheel motors and batteries that can be recharged via a regular electrical outlet for maximum environmental benefit.

Recharging allows the car to be driven about 100 km on battery power alone before the car’s four-cylinder diesel engine is needed to power the car and recharge the battery.

“A certain proportion of electrical vehicles will be necessary to meet the CO2 emission demands of the future. Since the Volvo ReCharge Concept combines an excellent battery range with a backup combustion engine, it is a very interesting concept,” says Magnus Jonsson, Senior Vice President Research and Development at Volvo Cars.