Lexus HS 250h

Never again let it be said that high-mileage hybrids are grim, joyless, or Spartan. The 2010 Lexus HS 250h sedan is the smallest and most economical car Lexus has ever built, but it’s unquestionably luxurious. Lexus has noted that more than 60 percent of luxury-car buyers would consider a hybrid if one were available. Well, now those buyers have a new option.

As of mid-April, the EPA hadn’t released mileage or emissions ratings for the new Lexus. But they’re expected to be close to those of its sibling, the all-new 2010 Toyota Prius, which achieved 51 mpg city / 48 mpg highway (50 mpg combined rating).

Lexus says the HS 250h will offer the best combined mileage of any luxury vehicle available in the US today, and will qualify as a Super-Ultra-Low-Emission-Vehicle (SULEV). The company also suggests its city mileage should be higher than that of the Smart ForTwo—which, for the record, is 33 miles per gallon.

The new Lexus HS will go on sale late in summer 2009. The company hasn’t yet announced pricing, though Toyota executives hinted to us that the base sticker might start between $30,000 and $35,000, with options that might carry it to $40,000 or more.

Lexus HS250h
Lexus HS250h

The HS 250h is the Lexus brand’s first dedicated hybrid, just as the Prius was for its parent brand Toyota. Previous Lexus hybrids were adaptations of existing vehicles, including the popular RX 400h crossover—replaced for 2010 by the RX 450h—the GS 450h sports sedan, and the full-size luxury barge LS 600h. But the HS will be sold just as a hybrid, with no gasoline-only version.

The comparison to the 2010 Prius is apt, since the two cars share the same basic platform. They both ride on a 106.3-inch wheelbase, though the Lexus HS 250h is 2 inches wider, half an inch higher, and a full 9 inches longer than its hatchback relative. The HS also has a larger 2.4-liter engine—similar to the one in the Toyota Camry Hybrid—against the 1.8-liter engine used by the 2010 Prius. The complete hybrid system in the Lexus is fully 40 percent more powerful than that of the Prius: 187 horsepower compared to 134.

So while the two cars have different bodies, different engine sizes, and certainly different personas, you can view the HS 250h as a new Prius with a trunk, a raft of luxury accoutrements, and a different tradeoff between fuel economy and features.

Not that there’s anything wrong with that, as Seinfeld might say.

Lacking the Prius’s high roofline and abrupt vertical tail, the more conventional sedan styling of the HS is marginally less aerodynamic than its hatchback sibling, with a drag coefficient of 0.27 rather than the Prius’s 0.25. Lexus has never offered a hatchback, so given that the HS is a relatively short five-seat sedan, that’s still a respectable figure.

Lexus buyers expect luxury, reliability, and features, and the HS 250h delivers those in spades. It offers such optional electronic gadgetry as Bluetooth connectivity, a heads-up instrument display, a front-view monitor with a 190-degree angle of view, and adaptive cruise control. Its navigation system incorporates real-time traffic and weather, and casual-speech voice recognition. It even lets the owner customize the levels of haptic feedback in the mouse-like controller mounted on the console.

The HS also includes leather trim, a moon roof, and swathes of insulation and thicker materials to reduce the noise, vibration and harshness that every Lexus owner dreads. Adding to the refinement is a sound-deadening inner layer in the windshield, exhaust flow optimized to cut noise, and even slower, softer-closing power window switches from the uber-luxurious LS sedan.

It’s not entirely clear how the HS relates to the two other compact Lexus models, the sportier IS and the more conventional ES front-wheel-drive sedan. It will clearly expand the brand’s green appeal, and perhaps offer an upgrade to Prius buyers who want to maintain 40-plus-mpg ratings but crave more luxury and a more upscale brand.

In the end, the HS is a new kind of car for Lexus. But if Toyota’s luxury brand has demonstrated anything over its 20 years, it’s that it can pioneer new ideas and make them a sales success.