For the most part, having both high performance and high fuel efficiency in a midsize sport sedan is about as likely as Dr. Phil becoming "Time" magazine's Person of the Year. However, an exception to this normally hard and fast rule is the 2009 Lexus GS 450h. By combining the Lexus Hybrid Drive system with the company's feisty 3.5-liter V6 engine, the GS 450h delivers the thrill of 340 horsepower along with fuel economy numbers about 30 percent better than a similarly potent V8 engine. That means zero to 60 in around 5 seconds, along with a combined fuel mileage estimate of 23 mpg. Furthermore, this Lexus is squeaky clean, as it also achieves Super-Low-Emissions Vehicle (SULEV) status.

Apart from its hybrid-specific instrumentation, wheels and badging, the 2009 Lexus GS 450h looks and feels much like its GS 350 and GS 460 stablemates. This means a nice handling and ride balance, handsome styling, top-notch materials and build quality, and an abundance of luxury features. Being the top of the GS series family, the GS 450h comes loaded with goodies such as a power rear sunshade, heated and ventilated front seats, rear side-impact airbags, rain-sensing wipers, adaptive front lighting, a rear back-up camera and a parking assist system.

Without a doubt, the 2009 Lexus GS 450h's combination of performance, luxury and fuel economy is impressive. But there's a price to pay for this trio of lovable character traits: several, actually. One is a sticker price approaching $60,000 -- the V6-powered but otherwise similar GS 350 lists for about $12,000 less, is still respectably quick and is rated at just 1 mpg less in combined driving than the 450h. Another drawback is the 450h's smallish trunk capacity. Although increased slightly this year to about 11 cubic feet, the hybrid's trunk capacity still rates a couple cubes less than its GS stablemates. And lastly, though certainly athletic, the GS 450h isn't as involving to pilot as traditional luxury sport sedans like the BMW 5 Series. But on the whole, Lexus' hybrid sport sedan doesn't make much financial sense, but it should appeal to buyers who want performance without much of a sacrifice in fuel economy.

The 2009 Lexus GS 450h midsize luxury sedan sits atop the GS lineup. It comes equipped with a full array of standard premium luxury features such as 18-inch wheels, adaptive suspension dampers, adaptive xenon headlights and a sunroof. Leather upholstery, heated and cooled front seats with driver memory settings, dual-zone automatic climate control, wood interior trim, Bluetooth, a back-up camera, keyless ignition/entry and a 10-speaker audio system with in-dash CD changer and auxiliary audio jack also come standard.

There are a handful of options to choose from, including a navigation system, satellite radio, a phenomenal 14-speaker Mark Levinson audio system, a safety-oriented pre-collision feature with adaptive cruise control, active antiroll bars and a rear spoiler. Conventional summer (performance) tires are standard on the GS 450h, but buyers have the option of getting run-flats in either summer or all-season guise.

The GS 450h's 3.5-liter V6 engine and separate high-output electric motor combine to generate up to 340 hp. The hybrid's power is transferred seamlessly to the rear wheels through a specialized continuously variable transmission (CVT). As with most hybrids, the GS 450h can start off and drive at low speeds solely under electric power, and then engage the V6 automatically when additional motivation is needed.

Performance is impressive at any speed, whether accelerating from a standing start or calling on midrange passing reserves at higher speeds. Zero-to-60-mph runs take a scant 5.2 seconds, and the gas/electric hybrid powertrain helps the 450h achieve EPA-estimated fuel economy ratings of 22 mpg city/25 mpg highway and 23 mpg combined. For comparison, the V8-powered GS 460 has 17/24/20 ratings, while the BMW 550i rates 15/23/18.

Standard safety features include antilock brakes (with brake assist), traction control, stability control and a total of 10 airbags. The latter include front and rear side airbags, driver and front passenger knee airbags and full-length head curtain airbags. Optional are Lexus Link and Lexus' Pre-Collision System. Pre-Collision uses a radar sensor to detect objects in front of the car, plus a computer that tracks vehicle speed, yaw rate and steering angle. If the computer determines that a collision is imminent, it immediately activates the seatbelt pre-tensioners and engages full power braking when the brake pedal is depressed.

In Insurance Institute for Highway Safety crash testing, the 2009 Lexus GS 450h scored the top rating of "Good" in both frontal-offset and side-impact tests.

The 2009 Lexus GS 450h provides composed and well-balanced performance, with a nearly perfect compromise between sport sedan responsiveness and touring sedan comfort. The ride is plush in the adaptive suspension's Comfort mode; when the driver is up for a more spirited romp, the Sport setting noticeably firms up the damping. When the optional active stabilizer system is added, body roll during cornering is also considerably reduced. One minor weakness involves the brakes, which some drivers find non-progressive and a bit touchy at first. This unusual pedal feel is quickly taken in stride, however, and the regenerative braking system otherwise stops the 2-ton GS 450h quickly and with reassuring authority.

In keeping with Lexus tradition, the GS 450h sports a luxurious and well-crafted cabin. Though spacious enough for five passengers, it accommodates four more comfortably, as the elevated rear center cushion makes for a tighter fit in the middle position. Genuine wood and aluminum trim complements the rich leather seating surfaces, and it's all put together with flawless fit and finish. However, the highly polished wood can annoyingly reflect glare at times, and the flip-down control panel located to the left of the steering wheel can get in the way of the driver's exit if left open. Trunk space is tighter than other GS models at only 11 cubic feet, owing to the placement of the hybrid battery pack.