Nouvelle sorte de démarreur pour sauver du fuel chez GM

[STONE_COLD]

DETROIT -- Two mid-sized General Motors cars will combine the starter and alternator to improve fuel economy.

The 2008 Chevrolet Malibu will get what GM calls a belt-alternator starter system, says Tom Stephens, group vice president for powertrain. The system eliminates the traditional starter. It uses a reworked alternator to start the engine with a belt.

To save fuel, the system shuts off the engine during stops and restarts it when the driver steps on the accelerator. It uses a 36-volt battery but keeps the 12-volt electrical system.

GM estimates it will boost fuel economy by about 12 percent if used with a fuel-saving continuously variable transmission.

In Europe, PSA/Peugeot-Citroen SA says it will equip some of diesel-powered cars this year with a starter-alternator similar to the Malibu's.

A mid-sized front-drive Saturn car with the starter-alternator system will follow the Malibu, Stephens says. The cars are on the Epsilon architecture, which will be used globally.

"We wanted to get (the technology) on our highest-volume car architecture," Stephens says.

GM's strategy is to put fuel-saving technologies into its high-volume vehicles. Toyota, by contrast, is touting huge fuel-economy gains on low-volume vehicles, such as the Prius.

This fall GM will equip 2,500 Chevrolet Silverado and GMC Sierra full-sized pickups with mild-hybrid powertrains. Mild hybrids use an electric motor to assist the gasoline-powered engine, but the motor alone does not drive the vehicle. The trucks will get a modified starter that assists the gasoline-powered engine.

The Saturn Vue sport wagon gets a similar system for the 2006 model year. Production begins in April 2006, a spokesman says.

The Ford Escape Hybrid, which goes on sale this fall, has a full-hybrid powertrain. The electric motor and gasoline engine can power the wheels separately or together.

[epsilon]

des systemes de ce genre (le moteur arrete à un stop et que qu'il repart à l'accélération) j'ai pas trop confiance en termes de fiabilité long terme