Lexus is leading the way in the luxury hybrid market with the introduction of the 2006 Lexus RX 400h. Based on the ultrapopular Lexus RX 330 SUV, the RX 400h offers traditional Lexus luxury combined with improved fuel economy and eco-friendly utility. Available in either front- or all-wheel drive, the SULEV-rated Lexus RX 400h uses a new hybrid system that combines the efforts of a 3.3-liter V6 engine with three electric motor-generators, scoring an EPA rating of 33 city/28 highway. Equipped with a continuously variable transmission, the Lexus hybrid SUV boasts an impressive 268 hp. That's 38 more horsepower than the RX 330. With a 0-60-mph time of just 7.2 seconds, the RX 400h's quick acceleration belies its frugal fuel consumption. Typically, the RX 400h gets underway with electric power until the computer deems it necessary for the engine to fire up. This makes for quiet takeoffs, but it also highlights other noises that can be intrusive.

To ensure a serene driving experience, Lexus added an acoustic glass windshield and a quieter radiator cooling fan. The battery pack, which is the heart of the hybrid system, is housed under the Lexus 400h's rear seat. With 30 modules comprised of eight cells per module its total peak power is 80-percent stronger than the Toyota Prius'. Another new piece of technology introduced in the RX 400h is an all-encompassing vehicle stability control system Lexus calls Vehicle Dynamic Integrated Management (VDIM). Instead of reacting to an already occurring driving situation, VDIM is designed to anticipate vehicle instability in every direction while making corrections.

On the road, the Lexus RX 400h waltzes up steep highway grades as if it was taking a stroll through the suburbs. It feels considerably faster than the RX 330, a vehicle it outweighs by 300 pounds. Additionally, the 400h hybrid has tighter suspension tuning than its Toyota Highlander Hybrid cousin, and this, along with its 18-inch tires, makes for a more engaging drive without compromising the plush ride Lexus buyers expect. The 2006 Lexus RX 400h may command an $11,000 premium over a base RX but it comes loaded with nearly every possible feature.

The standard equipment list includes items such as power-adjustable front seats, stability and traction control, second-row seats that slide and recline, dual-zone automatic climate control and a power rear hatch. Options on the RX 330 that have been made standard on the RX 400h include leather interior trim, a roof rack with rails, a one-touch open/close moonroof, a DVD navigation system with rear backup camera, a six-disc CD changer, xenon headlamps that swivel when you turn and 18-inch alloy wheels. Put all of this stuff on a regular gasoline-powered RX and the premium for the Lexus hybrid is about $3,000. Factor in a tax credit and the money you'll save on gas, and there's plenty to be said for driving the first hybrid luxury SUV.

Available in a single trim level with a choice of front- or all-wheel drive, the Lexus RX 400h is visually a dead ringer for its gasoline-powered RX 330 twin. The standard equipment list includes items such as power-adjustable front seats, stability and traction control, second-row seats that slide and recline, dual-zone automatic climate control and a power rear hatch. Also included are amenities like leather upholstery, a roof rack with rails, a one-touch open/close moonroof, a DVD navigation system with rear backup camera that shows what's behind you, a six-disc CD changer, xenon headlamps that swivel when you turn and 18-inch alloy wheels. Only three items are optional on the RX 400h: a rear-seat DVD entertainment system with wireless headphones, heated front seats and a Mark Levinson audio system.

In either front- or all-wheel drive, the Lexus RX 400h uses a new hybrid system that combines the standard 3.3-liter V6 engine with three electric motor generators. Mated to a continuously variable transmission, the 400h boasts 268 hp and a 33 city/28 highway fuel economy rating.

The RX 400h features standard front, side, head, and even driver knee airbags. Standard stability and traction control systems are fully integrated with the hybrid drivetrain, allowing them to anticipate a potential loss of control and react immediately. In NHTSA crash tests, the RX 330 resulted in a five-star rating (out of five) for all but the front passenger, which received a four-star rating.

Although it's a hybrid, the Lexus RX 400h drives a lot like the RX 330, an SUV we've always liked. Its electric motor may not sound like a V8, but its pull off the line is just about as strong. Ride quality is plush on the highway, and although the hybrid version's extra weight is apparent in turns, the RX 400h remains surefooted. Our only complaint is that engine noise can be intrusive, as the hybrid system gives the V6 more leeway to shoot up to redline under hard acceleration.

Read our 2006 Lexus RX 400h Long-Term 20,000-Mile Test

Inside the Lexus RX 400h, three round, chrome-rimmed gauges house the vital information, while the 7-inch navigation touchscreen displays the gas-electric power distribution, just like in the Toyota Prius. Aluminum trim gives the cabin a high-tech ambience. In back, a 40/20/40-split rear seat slides and reclines for maximum passenger comfort. The RX 400h offers 84.7 cubic feet of cargo space as well as a standard power-operated liftgate.