Lexus introduced what it says will be the world's first luxury gas-electric hybrid SUV Jan. 6 at a press conference at the North American International Auto Show.
The RX 400h will be powered by a V6 Hybrid Synergy Drive system that combines sub-eight second zero-to-sixty acceleration with fuel-efficiency equivalent to the current average for a four-cylinder compact sedan. The RX 400h will also be rated Super Ultra Low Emission Vehicle (SULEV), one of the most stringent emissions rating in the industry.
"The new RX 400h re-defines the midsize luxury SUV market while raising awareness and acceptance of hybrid gas-electric vehicles among luxury car and SUV buyers," said Denny Clements, Lexus group vice president and general manager. "This is truly a breakthrough in terms of hybrid gas-electric powertrains because, for the first time, it adds a new performance dimension to the traditional hybrid advantages of high mileage and low emissions."
Lexus says it created the car-based, luxury SUV segment with the launch of the RX 300 more than five years ago. For 2004, Lexus says it made significant enhancements to the luxury content, performance and safety features with the introduction of the RX 330.
The new RX 400h will become the premium model in the RX series, offering what Lexus describes as "smoother and quieter operation, increased performance, significantly better fuel economy and a host of high technology, safety and comfort features."
Vehicle Dynamic Management
The RX 400h will introduce what Lexus describes as "another industry first" called VDM, or Vehicle Dynamic Management. Monitoring a variety of sensors, the system is designed to anticipate the onset of a vehicle skid or slide and then helps correct the situation with a combination of braking and throttle control.
The new VDM system is less obtrusive than conventional VSC but ultimately more effective, according to Lexus.
More Powerful, Advanced Drivetrain
The 400h hybrid powertrain combines an electric motor with the 3.3-liter V6 engine found in the RX 330 to significantly improve low to mid-speed acceleration and overall fuel efficiency. The system is a "full hybrid," meaning that the RX 400h is capable of operating in separate gas or electric modes, as well as a mode that combines power from both.
The RX 400h will develop a peak system output of approximately 270 horsepower and deliver combined fuel economy significantly better than the current average compact sedan rating of 27.6 miles-per-gallon. Zero-to-60 acceleration will also improve over the current RX 330's sub-8 second time. The RX 400h with optional all-wheel-drive, which features a rear-drive electric motor, will accelerate quicker yet.
The RX 400h uses a regenerative braking system to further boost system efficiency. When the vehicle is coasting or the brakes are applied, the electric motor functions as a generator, capturing kinetic energy that would normally be lost as heat through the brakes and converting it into useable electricity to recharge the batteries.
One of the most remarkable features of the RX 400h, according to Lexus, is how similar this SUV is to its cousin, the RX 330. The computer-controlled powertrain blends power from the V6 gasoline engine, the electric drive motor and the generator. The driver does not feel the vehicle changing operational modes. In fact, the only giveaway is the absence of the traditional tachometer, according to Lexus. In its place, the RX 400h has an illuminated power meter that displays the level of power generated by the gas-electric hybrid powertrain.
The driver will also be able to monitor the gas-electric power distribution on the available seven-inch touch panel display screen that comes with the navigation system.
Luxury and Convenience Features
Nearly every feature available in the RX 330 is found in the RX 400h, with the exception of an exclusive RX 400h use of brushed aluminum accents inside that convey a high-tech look and feel to match its capabilities. The three-spoke steering wheel features easy-to-use controls for the audio system as well as the hybrid system's on-board computer monitor located in the center instrument panel.
"We believe the RX 400h will exceed the expectations of luxury vehicle buyers and establish a premium market for performance-oriented, fuel-efficient gas-electric hybrids," said Clements.
Powertrain: Engine - 3.3 liter V6
Electric motor(s) - Permanent magnet
Estimated total horsepower - 270
Expected EPA emissions rating - Super Ultra Low Emission Vehicle (SULEV)
Transmission - Electronically-controlled Continuously Variable Transmission (ECVT)
Wheelbase: 106.9 in.
Length: 186.6 in.
Width: 72.6 in.
Height: 66.1 in.