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.
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.
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.