New Car Reviews

2006 Lexus RX400h Hybrid

Kohala Coast, Hawaii Hybrids are hotter than bare toes in beach sand. The slightly wacky dualing powertrain idea introduced by Honda and Toyota five years ago is finally winning friends. From today’s half-dozen cars and trucks that use gasoline and electricity for propulsion, the hybrid fleet is expected to rise to fifty models and more than a million sales by 2010. Even Porsche plans to offer one.

The 2006 Lexus RX400h shows that Toyota is forging a hybrid path for the world to follow. Armed with a premium-brand aura, more than 400 hp, and a price in the mid-$40,000s range, this hybrid ventures beyond tree huggers. In addition to providing a squeaky-clean exhaust and exemplary fuel mileage, this one accelerates with V-8 gusto and cradles its occupants in leather-lined luxury. Being green has never been so easy.

The Clark Kent exterior has only subtle distinctions to separate the 400h from an RX330. But underneath the ordinary mid-size-SUV bodywork, there’s enough technology to amaze Dr. Science.

The main propulsion source is a 3.3-liter DOHC V-6 altered slightly from the RX330 configuration to produce 208 hp. Three electric motors pitch in on cue. One sends a supplementary 165 hp to the front wheels, and another can provide 67 hp to the rear wheels (and thus imbues the RX400h with all-wheel drive). During deceleration, both recharge 240 nickel-metal-hydride batteries housed under the cargo floor. A third motor starts the gasoline engine (which shuts down at stoplights), regulates the continuously variable transmission’s ratios, and generates electricity for recharging batteries and energizing the other two electric motors. The computing power needed to coordinate this propulsion operation would dim the lights at IBM.

Press the pedal to engage the full piston-electric team, and you’re whisked to 60 mph in 7.2 seconds, only 0.7 second slower than a V-8. Despite carrying 300 extra pounds versus an RX330, passing acceleration is smoother, because gearchanges are step-free. The sound track is the soft growl of internal combustion, muted as usual by Lexus, with added accompaniment. During deceleration and braking, you can hear the whine of gears and motors at work recouping energy.

Instead of a tachometer that would show the engine operating in a narrower-than-normal rpm band, there’s a meter to help you avoid squandering electricity and a center-dash screen that offers instantaneous fuel economy and other trivia. According to Lexus, EPA mileage is 30 mpg in city driving (where most hybrid benefits apply) and 26 mpg on the highway, yielding a combined rating 40 percent better than that of the aforementioned Cadillac. Towing up to 3500 pounds is allowed, but Lexus discourages off-road use.

The Lexus RX400h provides the well-to-do with a sacrifice-free ride to social responsibility and also points toward a new high-performance pecking order. Toyota’s next hybrid is a 4.5-liter V-8 and electric motor combo calibrated to deliver V-12-like performance in the next Lexus LS sedan.