The Good: The GS 450h provides dazzling performance and top-notch luxury all in an eco-friendly hybrid wrapper. GPS navigation and Bluetooth are only the start of a litany of tech features, most of which come as standard equipment. The Bad: Some voice-command niggles with Lexus's fifth-generation navigation system and minor gripes with the variable gear-ratio steering system were all we could come up with. The Bottom Line: With more horsepower than most sports sedans, a hybrid engine, and a long list of tech features, the Lexus GS 450h is a consummate package of comfort, performance, and technology. Blowing away the conventional wisdom that hybrid cars are hair dryer-powered eggs on wheels, the 2007 Lexus GS 450h shows that gasoline plus electric can equal breathtaking performance. A powerful V-6 abetted by a high-output permanent-magnet electric motor endows the world's first hot-rod hybrid with 339 horsepower and catapults it from standing to 60 quicker than the new Jaguar XK. But as a full-size, opulently appointed sedan, the 2007 Lexus GS 450h is not a sports car. It is an executive pseudo-eco-mobile aimed squarely at high rollers who want to feel good about their environmental footprints while flying along in the left lane of the highway between conference calls. In many respects, the GS 450h is a showcase of all the technology that Toyota Motor Company has in its arsenal. As well as its formidable propulsion arrangement, which includes a variable valve-timed engine and an ultralightweight boost converter, the car's performance features include a continuously variable transmission, regenerative braking, variable gear-ratio steering, and active variable suspension all as standard. Options include power-active vehicle stabilizer with Z-rated run-flat tires ($3,400) and Lexus's precollision system ($2,850). Inside, our test model came with voice-activated GPS navigation with integrated Bluetooth hands-free calling ($1,900), a 16-speaker Mark Levinson audio system ($1,780), heated and ventilated seats, adaptive cruise control, an intuitive park distance sensor, and all manner of comfort settings in which to enjoy our eco-friendly consciences. All told, our tester rang up at $65,794. The cabin of the GS 450h is very Lexus. A 6-inch screen sits in the center of a wood-trimmed dash, and clusters of buttons everywhere give the driver and the front passenger plenty of opportunity to customize the ride to their own comfort levels. The GS 450h comes with 10-way heated and ventilated power seats, Bluetooth hands-free calling, and Lexus's six-disc in-dash CD changer as standard. Our tester also came with the optional voice-activated navigation system, adaptive cruise control, and the upgraded 14-speaker Mark Levinson audio system, which is impressive as much for its excellent sound quality as it is for its broad range of 3-letter functions: from its ability to play MP3 and WMA-encoded CDs to its ASP (automatic sound leveling) and DSP (digital sound processing). The optional 14-speaker Mark Levinson audio system supports MP3 and WMA digital audio formats and sounds great. In addition to its 5.1 surround-sound audio capabilities, the upgraded stereo system supports DVD video and video CDs, which can be played back via the navigation LCD screen. Pairing our Sprint Fusic to the Lexus Bluetooth system took a little longer than it should have, thanks to the phone menu being accessed via the Information screen rather than the Menu button. Once paired, we found that voice dialing was straightforward and that the system was adept at recognizing our spoken phone numbers. The voice-activated navigation system was equally challenging. As we found in our time with the 2006 Lexus IS 350, one cannot just hop into a Lexus and rattle off speculative commands as is the case with a Honda or an Acura. A list of specific voice prompts must be learned and used in conjunction with the correct screen for the Lexus voice command system to be mastered. After some consultation of the manual, we found that (when in the correct screen) the voice-recognition system was adept at understanding destinations. One peeve that we have with the voice-recognition interface is the amount of time one has to input a voice command after pressing the steering wheel-mounted Talk button. After each push of the button, the Lexus pipes up with: "After the beep, please say a command," followed by a pause and the beep, which all takes about 5 seconds. Considering that the input of a destination can involve as many as five steps, this adds up to a large amount of wasted time. When possible, we preferred to program destinations by hand using the touch screen, which we found far more user-friendly. The ability to find destinations by entering a phone number was a feature we particularly liked. When fully programmed, the navigation system works well with a variety of screen configurations showing high-resolution maps, accurate turn-by-turn directions, and an impressive refresh\/recalibration speed. We preferred to program the fifth-generation Lexus navigation system by hand rather than voice. The other main cabin-based tech system in the GS 450h is dynamic radar cruise control, which uses a radar-based sensor to enable drivers to set a vehicle-to-vehicle distance between themselves and the car in front. As with other high-end cars we've tested, the GS 450h has three settings for this function (long, medium, and short) to allow drivers to tail cars at their chosen preset distance. With the relevant distance setting selected via a rocker switch on the steering wheel, drivers then use the regular cruise-control stalk to set speed in 5mph increments. In practice, we found the function more of a curiosity than a useful tool. Accustomed as we are to swift throttle response, the car's acceleration when under the radar's spell seemed to take an eternity. When the system acted to slow us down, engine braking was a little more noticeable, and on the occasion of a Toyota minivan cutting us off, the system beeped and flashed at us to inform us that our input was needed to avert disaster. However, we always felt the need to keep a foot poised over the brake pedal just in case, and found that the occasional dose of good old-fashioned pedal input was needed for us to keep up with the flow of the traffic. Dynamic radar cruise control enables drivers of the GS 450h to program a preset distance from the car ahead. Other comfort systems on the GS 450h include dual-zone automatic climate control with an air filter, keyless entry, a power headlight cleaner, and a power tilt and telescoping steering wheel. There's no doubt that the Lexus GS 450h is a hybrid: even if you miss the Hybrid logo on the rear footplate, the cabin instruments leap out to remind you that this is no ordinary leather-and-red-walnut-trimmed Lexus interior. After depressing the push-button start, the only clues that you're ready to go are the illuminated instrument panel--including a voltmeter in place of the tachometer and an LCD schematic involving a wheel and a battery--and the fact that the button has turned from red to green. Silently trundling out of the parking lot on electric power, we felt like we were in a large, gentrified Prius. Like the Prius and the 2007 Camry Hybrid, the GS 450h uses Toyota's Hybrid Synergy Drive system, which, as a "full" hybrid system, enables it to run entirely on gasoline, entirely on electric, or on a mixture of the two. A voltmeter replaces the tachometer in the GS 450h and is one of the more visible clues to the car's hybrid identity. If the hybridness of the GS 450h is no secret, then the fact that it is a performance car is less obvious. Not only is the GS 450h a hybrid--until recently a word that inspired images of golf carts--its bulky profile suggest leisurely comfort rather than blistering performance. And from the driver's seat, not a lot suggests that this is going to be a wild ride. Aside from the presence of a kW gauge in place of the tachometer, the cabin looks at first like any upscale Lexus. We knew from the spec sheet that it comes equipped with a 3.5-liter V-6 engine with continuously variable transmission and a high-output permanent-magnet electric motor. There are also other suggestions that the GS 450h will push the boundaries of hybrid performance: rear-wheel drive, active variable suspension, and four-wheel ventilated brakes are not the kind of thing that you find on an everyday sedan. But all this doesn't really sink in until you click the shifter over to S mode and squeeze down on the gas pedal. With its electric and gas systems working in concert, the GS 450h conjures up a breathtaking 339 horsepower. Breathtaking not just because it is more powerful than the 2007 Jaguar XK Coupe, which it beats to 60mph by seven-tenths of a second, but because the kick in the back when flooring the throttle is so unexpected. The GS 450h's formidable performance is further enhanced by its continuously variable transmission. Rather than a jolt-ridden sequence of upshifts, the car accelerates with preternatural calm--a bit like a train. In the absence of a tachometer or the telltale whine of the engine, the GS 450h prompts drivers in manual mode with a series of buzzes and flashes on when to change gear. These prompts act to notify the driver when to change up (that is, when engine revs are too high for the current gear) and when not to change down (when engine revs are too high for the selected gear). On closer inspection of the cabin, there are some subtle hints to the GS 450h's sporty alter ego. The central armrest slides back to reveal a cluster of buttons for setting the adaptive variable suspension (Sport or Normal) and the driving mode (Power, Normal, or Snow). The difference between the two suspension settings is immediately noticeable: attacking a winding road in Sport mode, and then coming back in Normal showed the extent to which damping firmness differs between the two. Less obvious was the difference between the driving modes, which are supposed to optimize the performance of the car for sport-driving, economy, and hazardous conditions; we didn't try Snow mode, but there was no clear difference in our experience between the other two. Other performance technology on the GS 450h includes variable gear-ratio steering (VGRS), which adapts the responsiveness of the car's steering to its speed; while traveling at speed, steering inputs have less effect than when crawling along in traffic or trying to park. While this sounds like a good idea in theory, in practice, we found that it made for awkward in-city driving, especially when stuck in traffic on a curved road. As the speed of the car is low, the VGRS sets responsiveness to its highest level, meaning that the slight turn needed to keep the car following the bend is translated into considerable oversteer, which requires constant correction. The GS 450h is rated by the EPA at 25mpg highway\/28mpg freeway--one of the closest sets of figures we have seen and due to the car's ability to use entirely electric power in town. In our week with the car, we observed just over 17mpg in mixed metro driving with a driving style more focused on performance than on economy. The GS 450h is rated by the state of California as a super ultra low emissions vehicle (SULEV). In keeping with its high-tech engine and interior, the 2007 Lexus GS 450h has an impressive lineup of advanced safety systems. As expected on a $50K-plus luxury sedan, ABS, brake assist and traction control come standard, as do rain-sensing wipers, a tire-pressure monitoring system, daytime running lights, and Lexus's Vehicle Dynamics Integrated Management (VDIM), which uses brake, throttle, and steering inputs to counteract loss of vehicle control. The GS 450h also incorporates a standard Pre-Collision Safety (PCS) system, which uses radar to detect possible obstacles ahead. If the system decides that a crash is unavoidable, it acts to pretension the seat belts and to apply brakeforce to mitigate the impact. Lexus differentiates itself from other luxury brands with the inclusion of adaptive front (high-intensity discharge) headlights and park distance control sensors also as standard. Optional safety equipment includes a power active stabilizer system, designed to increase rollover resistance by twisting the stabilizer bars. The system is available only with run-flat all-season Z-rated tires and adds an extra $3,400 to the sticker price. Those opting for the available navigation system will also get a back-up camera. A back-up camera works in conjunction with park distance control to ensure that the GS 450h avoids obstacles to the rear. Dual front airbags, front seat-mounted side-impact airbags, and driver's and front passenger's knee airbags provide plenty of protection for those up front, while energy-managing crumple zones give everyone onboard a chance in the event of a crash. As of this writing, the 2007 Lexus GS 450h had not been tested by the NHTSA for impact or rollover safety ratings. The GS 450h comes with a basic four-year\/50,000-mile warranty, with free maintenance for the first year or the first 7,500 miles. The car's drivetrain is covered for 6 years\/70,000 miles, with all hybrid components covered for 8 years\/100,000 miles.