Our High Gear Media colleague Bengt Halvorson has just driven the eagerly awaited 2010 Lexus HS250h. It's the first dedicated hybrid for Toyota's luxury marque, meaning it isn't offered in a gasoline-only version (just as the 2010 Toyota Prius is solely a hybrid).

Unlike the Prius, which maximizes gas mileage, the HS250h strikes a balance between fuel economy and the whisper-quiet high luxe that Lexus represents to buyers.  That means the EPA rates it at "only" 35 miles per gallon versus the 50 mpg figure for the 2010 Prius.

And those figures may be optimistic, if Bengt's experience is any guide. He saw about 30 mpg in mixed southern California traffic, dropping to 22 mpg on a hilly route that stretched the car's performance to its limits. He did admit to 46 mpg when he really worked at it, though.

Despite sharing a hybrid system and a wheelbase with the 2010 Toyota Prius, the 2010 Lexus HS250h is quite a different car. It's a sedan, rather than a hatchback. Its engine is larger and more powerful: 2.4 liters and 147 horsepower, versus 1.8 liters and 98 hp.

Overall, says Bengt, "the 2010 Lexus HS 250h is tight and quiet inside, thanks to details like an acoustic windshield and triple-layer door seals, but coarse engine noise makes itself known under acceleration." Which, as he notes, is not what Lexus buyers expect.

The culprit is weight. The HS250h weighs an astounding 600 pounds more than the Prius, putting it in the same category as the 2009 Toyota Camry Hybrid--which, as Bengt notes, is quicker.

So what's the payoff? "Our indifference about the driving experience was replaced by gadget lust," says Bengt. "The HS 250h has enough of the latest tech features to rival all but the brand’s LS 600h flagship."

Reviews of the HS250h's styling, hardly the most elegant example of the Lexus "L-Finesse" approach, have been mixed at best. From our visit to the New York Auto Show with 9-year-old car connoisseur Luc: "It doesn't look like a Lexus very much."

We'll have more details on this car soon, including the all-important price. And we look forward to bringing you our very own GreenCarReports.com test drive later this year.

2009 Detroit auto show

2009 Detroit auto show