2007 Lexus GS450h

The Big Island of Hawaii is a land of surprises. Along the warm, dry Kona Coast it's sunshine, swimming, and golf. But just ten miles away, along the cross-island Saddle Road , a torrential rain is pummeling down, while a blizzard scours the island's twin volcanic peaks.

So it was an unexpectedly appropriate place to go for our first drive of the 2007 Lexus GS450h, a sedan that delivers a variety of its own surprises. The new model could very well redefine both the Lexus brand and the concept of hybrid-electric vehicles.

"Hybrid" is, of course, what the little "h" stands for, making this the second gasoline-electric offering in the Lexus lineup. The first, the RX400h, debuted barely a year ago. A version of the automaker's crossover wagon, it's proved both immensely popular and quite controversial. Like the little Prius sedan sold by parent company, Toyota , Lexus bills the RX400h as an environmentally friendly vehicle whose high-mileage technology reduces both emissions and reliance on imported oil.

In real-world use, the RX is more about feeling good than helping Mother Earth. Some reviewers, including those at TheCarConnection.com and The New York Times, have gotten just 21 mpg. Polling owners, the enthusiast site, GreenHybrids.com, got the average closer to 25 mpg, still a significant shortfall from the 33 City/28 Highway sticker. But if you don't save much fuel, there's the feel-good factor - and the access to the diamond commuter lanes with one person onboard, offsetting the steep hybrid price penalty.

Well aware of the controversy, Lexus is nonetheless still singing a green tune as it prepares to launch the GS450h. But it is fine-tuning that message. The emphasis here is on environmentally sensitive performance.

Cleaner than the average car

The sedan, boasted chief engineer Shigetoshi Miyoshi, is "80 percent cleaner than the average car." But during a background briefing, he put the real emphasis on the fact that the new hybrid is not only the fastest-ever Lexus, but with a 0-60 time of 5.2 seconds, quicker than a Porsche 911 with the Tiptronic transmission. Top speed is a limited 131 mph for the U.S. version.

Will you also get better mileage? Well, it depends. Almost certainly better than a 4.5-liter V-8, which officials claim is what you'd need to get comparable performance - and why the 3.5-liter sedan is designated the GS450h, rather than GS350h. According to Lexus, the '07 hybrid should match the fuel consumption of a stingy, 2.5-liter in-line four, rated 27 mpg City and 28 Highway.

Well, that's what the window sticker is likely to show. But we wouldn't expect that in everyday use. Sure, in heavy L.A. traffic, you'll spend time in electric-only mode. But stomp on the drive-by-wire throttle and you're going to drain a lot of that imported petrol. During several admittedly brief runs around the Big Island , our test GS delivered results ranging from 19.3 to 24.4 mpg. Steep hills and hard acceleration, as you'd expect, quickly slashed away at the numbers.

Now, as we tore through the Hawaiian countryside, we have to admit, we weren't all that worried about fuel economy. This hybrid-electric proved an absolute, er, gas to drive.

Flat-out performance is exhilarating. The throttle nailed, you quickly sank back into the sedan's well-bolstered seats. Thanks to the "electric supercharging" system, the GS kept pulling as long as there was power in the batteries. And we found no noticeable loss in performance as we climbed to higher altitudes on this well-terraced island.

With last year's introduction of the GS sedan, Lexus took a great leap forward. As the division's general manager, Bob Carter, readily admits, this is not a brand known for its high emotional quotient. Parent Toyota is trying to change that. It has set up a separate Lexus board of directors, engineering arm and design center. And the '06 GS made great use of the division's stylish new design theme, known internally as L-finesse.

Lexus chose not to plaster the word, "hybrid," all over the vehicle, preferring discreet badging and otherwise subtle visual differences from the standard GS sedan.