According to Tom Watson, Ford's hybrid systems propulsion manager, the little turbo diesel suits the parallel electric power system well. You might as well have a substantial electric motor, he points out, because a diesel's high compression ratio—18:1 or more—demands a pretty beefy starter motor anyway. And by smoothing out the load on the diesel engine, the electric-drive system helps mightily in minimizing emissions of nitrogen oxides and particulates.

Both the engine and an electric motor of about 30 kW drive the front wheels through a six-speed transmission with electronic manual shifting. Like the Lexus RX400h luxury sport-utility hybrid, the Reflex uses an additional electric motor (of 15 kW) to drive the rear wheels and provide all-wheel drive. Ford quotes fuel economy of 5.9 to 3.6 L/100 km (40 to 65 mpg) but stresses that it is accompanied by sporty performance: acceleration from 0 to 60 mph (0 to almost 100 km/h) in less than 7 seconds.

Photovoltaic solar panels on the roof and in the lights help too, because even though they deliver "watts, not kilowatts," as Watson says, they can lighten the load on the high-voltage batteries. Also, the panels power a small fan that vents heat from the car when it is parked.

If public response to a sporty high-mileage hybrid coupe is positive, Watson says, perhaps "the stigma of diesels in North America can be overcome by the hybrid's image."

2006 Chrysler 300C (Heritage Edition)

The most polite—and effective—headlights on U.S. roads

Chrysler's 300C caught on fast after its U.S. introduction in the 2004 model year. It's a powerful, stylish four-door sedan with a V8 engine driving the rear wheels—a genre that U.S. makers had ignored for 10 years while focusing on sport-utilities and light trucks. To improve fuel economy, an automatic control system shuts the valves to four of the eight cylinders when the load is light, giving it a rating of 13.1 and 9.0 L/100 km (18 and 26 mpg) in the U.S. Environmental Protection Agency's city and highway driving simulations.

The really new technology this year comes up front, in the headlights. Called SmartBeam by developer Gentex Corp., of Zeeland, Mich., it switches on the high beams when needed, something U.S. drivers do only about 25 percent of the time. It's a problem that a U.S. Department of Transportation study identified back in the 1960s. SmartBeam uses forward-facing CMOS image sensors, effectively a camera on a chip, built into the interior rearview mirror. The technology keeps the brights switched on until it detects either the headlamps of oncoming vehicles or the taillights of vehicles ahead, then switches to the low beams. To avoid distracting approaching drivers, the system fades the high beams on and off.

Interestingly, the first attempt at such control was made half a century ago, when diodes were big and fragile and programming was what you heard on the radio. The General Motors Autronic system (1952 to 1958) switched the high beams according to the light that reached a dashboard-mounted direct-current phototube—an anode and a light-sensitive cathode enclosed in a glass tube. This photocell increased current proportionally to the light that entered it. The job was not done well, but it is amazing that it was done at all.

Chrysler calls this car the Heritage Edition to commemorate the 50th year of its 300 series, famous particularly for the 1957 Chrysler 300C, renowned for its performance. Limited production of the US $36 000 Heritage Edition is scheduled to begin next month. The SmartBeam system was launched last year on luxury vehicles from General Motors Corp.'s Cadillac and Chrysler's Jeep; it also will be fitted to BMW's 5-, 6-, and 7-Series models in Europe.

2007 Chevrolet Tahoe/GMC Yukon

You've got mail. It's from your car.

The latest Chevrolet Tahoe sport-utility and its GMC Yukon twin are hardly examples of advanced automotive design. Their rear axles are live, rather than independently suspended as on virtually all European cars. Their V8 engines are refined versions of a decades-old design. And these sport-utilities are bigger and heavier than almost everything sold for passenger use in Japan or Europe. Like Japan's kei cars, they're designed for a specific use in a single country: hauling up to eight people and their luggage, even while towing as much as 3500 kilograms.