Precept sets tone for green show

GENERAL Motors has provided the first glimpse of its Precept concept car, expected to be one of its main attractions at the upcoming Detroit motor show.

The teardrop-shaped Precept is powered by diesel and electric motors and is claimed to be capable of achieving fuel economy of 80 miles per gallon (about 3.5 litres/100km).

Ford's answer to the Precept is known as the Prodigy, and this vehicle will also make its debut at the Detroit motor show, which starts on January 9.

Both the Precept and Prodigy were developed under the US Government-sponsored Partnership for a New Generation of Vehicles (PNGV).

The industry-government alliance aims to build by 2004 production-ready prototypes that can offer triple the fuel economy of a current family sedan without sacrificing performance.

"Eighty miles per gallon really pushes you to the edge of the envelope," GM's executive director of Advanced Technology Vehicles, Robert Purcell, says.

Although the Precept and Prodigy are far too expensive to mass produce, their pioneering technology will filter down to production cars in the foreseeable future.

The Precept uses a battery-powered electric traction system to drive the front wheels and a lightweight 1.3-litre, three-cylinder, turbocharged direct injection diesel to power the rear wheels.

The electric motor derives its charge from either a nickel hydride or lithium polymer battery. Regenerative braking is used to channel energy that would otherwise be dissipated as heat into charging the battery.

Designers of the Precept have drawn heavily on the styling cues that distinguished the EV1 concept car - displayed at the 1998 Detroit motor show.

Drag has been minimised by using a camera system instead of door mirrors while exterior door handles have been eliminated altogether.

Further aerodynamic gains have been made by using special air openings behind the rear wheels in lieu of a front-facing grille.

Ford's Prodigy also uses cameras instead of mirrors, but its styling is altogether more conventional.

Like the Precept, it uses a combination of diesel and electric power to attain fuel economy of up to 70 miles per gallon (about 4 litres/100km).

Its kerb weight has been kept down to 1085kg thanks to extensive use of lightweight (and expensive) materials such as aluminium and titanium.

GM, Ford and DaimlerChrysler are estimated to have spent close to $1.6 billion on developing alternative-fuel vehicles last year.

DaimlerChrysler will not display a hybrid vehicle at the Detroit motor show but is likely to unveil one later in the year.