Flaunting it

BMW is about to take its flagship sedan and give it a green makeover. According to BMW spokesperson Bill Scully, in the 2008 or 2009 model year customers will be able to lease "dual-fuel" V12-powered BMW 7-Series cars powered by both gasoline and hydrogen.

With a flip of the switch and a barely perceptible hiccup, the driver will be able to run his or her big V12 on super-cooled liquid hydrogen. "It’s a limited-production vehicle and a good platform to demonstrate the capabilities of hydrogen," Scully said. The BMW would have a range of 185 miles on gasoline and 125 on hydrogen.

It’s not surprising that the long-wheelbase $117,000 760Li is limited production, because it’s a car for presidents and corporate heads. According to Edmunds.com, "The BMW 7-Series is the most popular chauffeured car in Germany because it shuttles occupants in swift and silent luxury, providing rear-seat passengers with enough room to stretch out and take a nap between power meetings."

The Web site describes the V12 model as "a monster that gobbles up interstate at a rate usually reserved for exotic sports cars."

Of much the same cloth is my current test car, an Audi A8L W-12. I’ve previously tested the Volkswagen Phaeton, which has much the same underpinnings but somehow wasn’t nearly as elegant in VW form. The A8L is nothing if not elegant, with a massive but sculpted shades-of-the-Maybach Teutonic shape. As with the BMW, it is especially coddling to rear-seat passengers, who can enjoy watching DVDs in the back of front headrests, adjust their seats to a comfortable position and even enjoy a beverage from the refrigerator (complete with glasses) tucked behind the rear armrest. (My girls made much of this particular feature.)

The $122,520 A8L offers a list of features to warm the heart of any techno-geek. There’s a six-speed automatic with Tiptronic, quattro IV all-wheel drive, adaptive air suspension with automatic load leveling, electronic stabilization, xenon headlights, an acoustic parking system (it beeps when you’re about to hit something), no fewer than 10 airbags, voice-controlled and Bluetooth-enabled phone, and on and on. The "driver interaction system" is better than BMW’s iDrive, but still annoying.

But probably most people would order this version of the A8 for the silky 6-liter, 450-horsepower, five-valve-per-cylinder all-aluminum V12 engine. Think of two V6 engines linked together in a W formation and you have the idea. Like the Jaguar V12, this power plant is a model of super-smooth power-on-demand technology.

The car can hit 60 miles an hour in only five seconds and tops off at 130 mph. It may be intended for chauffeurs, but it is still fun to drive yourself. Some reviewers have complained about dead-feeling steering but I thought it was pretty responsive.

It’s interesting to speculate on the fate of 12-cylinder cars in the age of $2.50-per-gallon gasoline. History teaches us that the 12- and 16-cylinder behemoths of the 1930s were done in by the Depression. It’s likely sales of top-end vehicles will slide in the same manner as big SUVs.

Actually, the fuel economy of the W12 (15 in the city, 21 on the highway) could be worse. But fuel prices are likely to continue heading north, and that must be making some luxury carmakers nervous indeed.