In April 2005, Toyota's luxury division launched the industry's first upscale sport utility vehicle with a gasoline/electric hybrid powertrain. Introduced at the 2004 North American International Auto Show, the hybrid-powered SUV had first been seen in concept form a year earlier. For 2007, it gets a few more bells and whistles.
Closely related to the gasoline-powered Lexus RX 350, which falls into the midsize luxury SUV segment, the RX 400h has the Lexus Hybrid Drive system. Lexus General Manager Denny Clements says the electric motor can operate at 12,000 rpm, which is twice the speed of the Prius' motor. Peak output totals 268 horsepower, which is about on par with output in the regular RX 350.
The RX 400h also has earned a SULEV (Super Ultra Low Emissions Vehicle) rating. Clements noted that driving the RX 400h round-trip between Los Angeles and New York nine times would produce fewer smog-forming emissions than painting a room with a gallon of house paint.
The all-wheel-drive system features a separate rear-wheel-drive electric motor; front-wheel-drive models are also available. A new Vehicle Dynamics Integrated Management system combines stability control with new electronic braking technology.
The 400h rides on 17-inch wheels, with 18-inch wheels optional. In 2007, the SUV gets a new blue badge on the rear, plus new side badges.
The RX 400h's appearance differs only modestly from the regular RX 350. Styling revisions include round fog lamps and an additional opening on the front bumper fascia for cooling powertrain components. The RX 400h is an inch longer than the RX 350 and weighs 300 pounds more.
The RX 400h's five-passenger seating and interior space are similar to the RX 350's. Rather than the usual tachometer, the dashboard contains an illuminated battery-power meter. The steering wheel contains controls for the hybrid system's monitor and the stereo.
The backseat has been raised 0.7 inch to accommodate the battery pack underneath. Thirty battery modules are split into three groups, each with a dedicated cooling fan.
In 2007, the front passenger seat gains 10-way power adjustment, there's a new coin holder in the center console, and the wood-trim option is available with all new interior colors. Voice activation has been added to the optional navigation system, as has a rearview camera. The optional rear-seat entertainment system gets a bigger, 9-inch screen for 2007, and a Mark Levinson audio system is available once you add the navigation system.
Under the Hood
Combining a 208-hp, 3.3-liter V-6 and electric motor-generators, the second-generation Lexus Hybrid Drive powertrain generates 268 hp total. A continuously variable transmission sends that energy to the wheels. The full-hybrid system can operate in gas or electric mode, as well as a combination of both. Lexus says the gas engine starts at a lower power level, which makes the transition between power sources harder to discern. Like the RX 350, the RX 400h can tow up to 3,500 pounds when properly equipped.
Antilock brakes incorporate electronic brake-force distribution and brake assist. Side curtain airbags, seat-mounted side-impact airbags and a driver's knee airbag are installed. An Adaptive Front-lighting System can swivel in accord with the front wheels to better light curves in the road. The AFS system is a standalone option for 2007, and the 400h gets a tire pressure monitoring system. Also new is an optional adaptive cruise control feature that can slow the vehicle automatically if it gets too close to the vehicle in front of it at highway speeds.
Hybrids might be known for fuel-saving capabilities, but performance reigns supreme in the RX 400h. This SUV zooms confidently and effortlessly from a standstill to highway speed, and it's difficult to discern exactly when the gasoline engine comes into play. Once it does, though, noise from the V-6 is more pronounced than expected from a Lexus, and it quiets down properly at speed.
The ride is pleasant and steering is easy on smooth roads. Bright, recessed gauges are easy to read. You get a full luxury experience, bountiful powertrain response and impressive city fuel-economy figures with this SUV, but the price is hefty.