PHOENIX, Ariz -- Most people old enough to remember the gas shocks of the 1970s, and the tiny cars the Toyota Motor Corp. was lucky enough to be shipping to America at just that time, probably never imagined that some day it would be possible to spend over $100,000 for a large, high-tech Toyota luxury sedan.

But that moment has arrived, with the launch of the Lexus LS 600h L sedan, a car designed to redefine what is meant by "top of the line" in the U.S. car market. This is a tall order, and it's no easier to be sure that the $104,000 Lexus LS 600h L will succeed in its ambitious quest after you've driven it than before.

Pretty much since the dawn of the motor age, "top of the line" has been synonymous with power, presence -- size, if you prefer – and, at least recently, a European pedigree. In the 1950s and 1960s, big Cadillacs were "the standard of the world." Today, European names, such as BMW and Mercedes-Benz dominate the top of the motoring food chain, at least when it comes to ultra-luxury sedans. The 12-cylinder versions of the BMW 7 series and Mercedes S-Class sedans are the benchmarks for sedans that fly above the $100,000 ceiling – a class that also includes the W-12 equipped Audi A8, the Bentley and Rolls Royce brands.

The Lexus LS 600h L sedan represents Toyota's effort to rearrange that formula, adding words such as, "clean," and "efficient," "high-tech" and "Japanese" to the list.

The LS 600h L is a technology showpiece, wrapped in a design that pays homage to the Teutonic benchmarks. To achieve the horsepower needed to compete with the German 12-cylinder super-cars, Lexus combines a 5.0 liter V-8 engine and an electric drive system that together to produce 438 horsepower. That power is sent to all four wheels through a continuously variable transmission and an all-wheel-drive system. In contrast, the BMW 760 Li and the Mercedes S600 are rear-wheel-drive cars.

Using a hybrid-electric drive, along with fume-scrubbing technology such as a "hydrocarbon adsorber" that soaks up fuel fumes during cold starts, Lexus says the LS 600h can achieve a super ultra-low emission vehicle (SULEV) status, meaning it's about 70% cleaner than the cleanest of its rivals, the company says. The EPA rated mileage for the LS 600h is 20 city, 22 highway, compared to 19 highway and 12 city for the 510 horsepower Mercedes S600.

The obsessiveness that Toyota's engineers have brought to the development of the LS 600h is hard to overstate. Consider this from the materials handed to reporters who attended the company's drive event a few weeks ago: "Camshafts, piston pins and crankshaft are polished to a mirror finish to reduce friction areas." And did I mention that the car has an optional system that allows it to park itself? But at this point, who doesn't know that, given the saturation broadcast of the commercials in which this feature is the star?

The problem for Lexus is that the LS 600h shouldn't seek to compete directly with the German uber-sedans, because it isn't what people who love those cars really want. It's something else.

On the road, and on test tracks at Toyota's Arizona proving ground, the Lexus LS 600h does remarkable things. It has an optional "advanced pre-collision system" that can detect when the car is about to hit an obstacle, and automatically help the driver brake and steer out of harm's way. There's even a system that can detect when a driver is nodding off, and sound a buzzer and electronically tap the brakes.

The car sails smoothly and quietly at over 100 miles an hour on a closed track – an experience few actual buyers will have.

But the LS 600h is still a Lexus, not a German supercar. The German uber-sedans have big horsepower numbers, but boast equally big or bigger figures for torque -- 612 pound-feet in the case of the S600 compared to 385 lb-feet for the LS. Torque is key to providing that feeling of mastery when powering away from a stop, or zooming around some slowpoke on the freeway. This what makes the German supercars feel aggressive and sporty -- and compensates their owners for the annoyance of dealing with features such as the BMW iDrive system.

The LS600h is certainly not slow. But the combination of the hybrid engine, all-wheel-drive system and the CVT transmission deliver the power in a much less visceral way. Like the standard LS, the dominant emotion you have behind the wheel of an LS600h is tranquility.

Moreover, if your values are such that you really want to save gas, flogging the LS 600h to its limits isn't the way to do that. Driven hard on the track, the car's computer puts mileage in the teens. Driving at a more sedate pace on streets and highways around Phoenix, I managed to coax my mileage computer up toward 25 mpg. Not bad for a car that weighs 4,332 pounds -- 717 pounds more than an LS460, largely due to the battery pack and all-wheel-drive system.

Still, Lexus engineers and marketers clearly wish this car had more eye-popping EPA mileage numbers. A standard long wheelbase LS 460, with a V-8 engine, costs $71,000 and is rated at 18 city, 27 highway. So saving money on gas isn't a real reason to trade up to the hybrid LS, for an extra $33,000.

In fact, the LS 600h begs larger questions. The LS 600h may be a rational, "green" choice for someone whose alternatives are defined as buying a 12-cylinder German sedan, or buying the hybrid LS. The hybrid LS is cleaner and more fuel efficient than those German uber-cars. Taken on its own terms, the LS 600h L should find success with the power brokers of Hollywood, Palm Beach and Greenwich, Conn. who want to be seen as both dominant and progressive.

But a wealthy person whose priority is reducing greenhouse gases would clearly do better to take $104,000 and buy four Toyota Prius sedans -- one for him or herself, and one each for three friends now driving gas guzzlers.

Or better yet, buy one Prius, (make it the Touring Edition that starts at $23,070) and use the remaining $80,000 and change to subsidize the efforts of a student or researcher who wants to tackle the many challenges confronting green vehicle technology, such as how to develop a commercially viable plug in hybrid.

After all, whether you drive a Prius, or the LS 600h, you'll probably get where you are going at the same speed.

Using a hybrid-electric drive, along with fume-scrubbing technology such as a "hydrocarbon adsorber" that soaks up fuel fumes during cold starts...

Driving at a more sedate pace on streets and highways around Phoenix, I managed to coax my mileage computer up toward 25 mpg. Not bad for a car that weighs 4,332 pounds -- 717 pounds more than an LS460, largely due to the battery pack and all-wheel-drive system.