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This article is from our archives and has not been updated and integrated with our "new" site yet... Even so, it's still awesome - so keep reading!

Published on Sun, Jul 17, 2005

By: The LACar Editorial Staff

© All photos by Harvey Schwartz


With the success and experience gained in producing gas-electric hybrid vehicles for the past several years, Toyota has finally transferred that gas-electric hybrid technology to the Lexus luxury brand. The all-new 2006 Lexus RX400h is the world's first hybrid powered luxury sport utility vehicle. And it's just in time, as fuel prices go through the roof and you have to dig deeper to pay for just ten gallons of fuel. The Lexus RX330 has gained a solid reputation as being one of the finest mid-size luxury sport utilities, and now the RX400h makes it even more appealing to own. I'm not just speaking about the improved gas mileage, 18/24 city/highway mpg for the RX330, verses 25/35 city/highway for the all-new RX400h. That's quite an improvement, but there's more. The RX400h is faster and more powerful. The RX400h uses the same 3.3-liter DOHC 220 hp V6 engine, but minus the starter, alternator, and serpentine belt to make room for the electric motor. Power is detuned to 208 hp at 5,600rpm, verses the RX330's 220 hp at 5,600rpm. However, when you add the gas and electric motors together, you have 270hp.

Put your foot down on the throttle, and you'll feel the added acceleration as the RX400h gets to 60 mph from standstill in just 6.9 seconds (verses the RX330 time of 7.6 seconds). Not bad for a 4,365 pound hybrid-powered vehicle. You can also tow up to 3,500 pounds. The all new, electronically operated all-wheel-drive system comes standard, giving the RX400h excellent traction and handling in all types of weather conditions, driving on or off the road, but not too far off the road. Speaking of handling, the RX400h borrows the excellent independent suspension found in the RX330, MacPherson struts, coil springs, gas-charged shocks and stabilizer bar up front and dual link struts, coil springs, gas-charged shocks and stabilizer bar in the rear. The gas-electric hybrid engine, transmission, power steering and power-assisted steel disc brake system are all new and available only in the RX400h. Let's take a closer look at these components, and how they make the RX400h so fuel efficient and powerful, utilizing the latest technological advances in hybrid automotive engineering. The RX400h luxury hybrid is defined as a 'full hybrid,' which means that it's capable of operating in electric-only or gas engine-only mode, as well as a mode that combines the power of the gas engine and electric motor.

On the gated shifter, you'll see D for drive and B for transmission braking - emulating a downshift into a lower gear (the RX400h actually has a continuously variable transmission). The 3.3-liter V6 has been modified for smooth integration with the hybrid system, including revised calibrations for the VVT-I system and electronic throttle control system. Because the engine often shuts down at rest and when running on electric motors only, the conventional engine-driven power steering pump is eliminated and the water pump and A/C compressor are now electrically powered. This translated to less parasitic losses to the engine and lower fuel consumption. The alternator is no longer needed as battery charging is handled by the hybrid system's motor-generators. The hybrid system uses a 288-volt DC Nickel metal hydride (Ni-MH) battery pack that's installed under the rear seat. The battery's power is directed through a 'boost converter' that raises voltage to 650V DC. An inverter changes this to 650V AC, providing its elevated power to a front-mounted 123KW electric motor. Three motor-generators are employed in the hybrid powertrain. Known as MG1, MG2 and MGR, each has specific functions and each do double duty as both drive motors (except MG1) and generators. The generator driven by the engine (MG1) can charge the battery pack or other electric motors as needed. Power from the gas engine and front electric drive motor (MG2) is distributed to the drive wheels via a planetary gear-type continuously variable transmission (CVT), which eliminates specific gear ratios. Two planetary gear units are used in the system. The Power-Split unit divides the engine's drive force two ways: one to drive the wheels and the other to drive the MG1 so it may function as a generator. The Motor Speed Reduction unit reduces the speed of MG2 and increases its drive torque, significantly boosting acceleration performance.

In addition to its motor-generator duties, MG1 adds two functions: one as a starter motor for the gas engine; and two, by regulating the amount of electrical power it generates (which varies its rpm), MG1 controls the output speed of the transaxle through the planetary gear set-without clutches or viscous couplings. In this way, the RX400h eliminates the 'shift-shock' that can be felt in conventional automatic transmissions. The RX400h uses an innovative electric all-wheel drive system that employs a separate 50-KW electric motor (MGR) at the rear to provide additional drive torque on demand. The system electronically varies torque distribution between the front and rear axles, depending on traction conditions. The Lexus hybrid system also allows extended electric-mode operation during low speed or stop-and-go driving conditions. The permanent-magnet front electric drive motor (MG2) produces peak torque from zero-to-1,500 rpm, giving the RX400h powerful and instantaneous response that is felt most clearly in city driving and in merging/passing maneuvers. All systems are seamless never letting you feel or otherwise notice the transitions from electric to gas engine, front wheel to rear wheel drive. A regenerative braking system further boosts system efficiency. When the RX400h is coasting or the brakes are applied, the electric motors function as generators, capturing kinetic energy that would normally be lost as heat through the brakes and transforming it into electricity to recharge the batteries. As a result of no belts or hydraulic liquids, the steering system is also electric (EPS) using rack & pinion steering with electronic power assist. A new dynamics management function called the Vehicle Dynamics Integrated Management system (VDIM) introduces the next generation of stability and traction management to Lexus. VDIM manages all dynamic functions including ABS, EBD, Brake Assist, TRAC and VSC, and provides cooperative control for the regenerative brakes and the electronic power steering (EPS) boost characteristics.

The key to DVIM lies in a new Electronically Controlled Brake system (ECB), which allows precise control over the other dynamic systems and, according to changes in their balance during driving, will correct vehicle behavior before it can become unstable. Under guidance from VDIM, precise brake pressure control, at individual wheels, allow optimized operation of the vehicles dynamic handling systems that employ the brakes (ABS, Brake Assist, VSC and TRAC). VDIM also interfaces with the Electronic Throttle Control system, allowing it to modify vehicle power when needed, and with EPS to optimize steering assist for each situation. Because VDIM controls all of the dynamic handling systems and can employ them collectively, it can quickly detect the onset of instability and make appropriate corrections. The system's ability to operate 'proactively' means that corrections to vehicle attitude are typically faster, more accurate and more subtle than conventional stability systems, making VDIM feel smooth and essentially transparent to the driver. Coupled with a new electric AWD system, VDIM significantly enhances the RX400h's dynamic qualities and ultimately expands its performance capability while maximizing driving pleasure and safety. The all-new 2006 RX400h is the most advanced gas-electric hybrid system in the world with an incredible amount of computing power, speed and ability. Driving the RX400h is a whole new feeling because of its silence and added passing power. One of the most stylish of luxury sport utilities on the market, the all-new RX400h distinguishes itself further from the RX330 with a newly styled front bumper for improved cooling, a new grille design, round, projector beam foglamps, new taillight clusters with LED lamps, specific 18x7 cast aluminum wheels with RX400h specific 235/55R-18 rubber that is softer for improved handling (a harder rubber compound for better fuel mileage is not needed). Outside, the Lexus RH400h continues the Lexus tradition of the total package with a sleek, clean overall look with no cladding yet with pronounced wheel-well arches that give it a rugged look. The large headlamp housings are raked back into the hood and feature HID headlamps with auto-leveling, and an adaptive front lighting system that improves road visibility in turns. The rear taillight housings merge with the black window glass and feature LED brake and taillights for longer life and quicker 'turn-on' time. A standard integrated black rear spoiler and 3in. wide polished stainless steel exhaust tip adds to the sporty look. The front door glass is water-repellant.

The body structure and paint is heavy duty with a highly rigid steel monocoque construction, a high level of rust protection with zinc-plated steel on the hood, doors and front fenders, anti-chipping paint is applied to the rocker panels, and wheel housing arch sections, and soft chip primer is applied to the hood for improved anti-chipping. Sound deadening material located throughout the vehicle is designed to reduce noise, vibration and harshness. UV reducing glass is used for all windows. Acoustic-laminated windshield glass further reduces noise. Standard convenience features include a standard power rear liftgate, rain-sensing wipers including headlamp washers, variable intermittent windshield wipers, rear intermittent wiper, auto on/off headlamps, round projector-type fog lamps integrated into the front bumper, auto-dimming/heated electrochromic side mirrors, roof rack, Lexus chrome scuff plates that light-up when the door is opened, and towing package. Interior features includes Regency leather interior trim and seating surfaces, leather trimmed/power tilting/telescoping, three-spoke steering wheel and leather shift knob, fabric covered sun visors with lighted vanity mirrors and slide extensions, aluminum color interior accents on all doors, console, instrument panel gauge bezels, switch plates, around shifter gate and shift knob. You also get chrome door handles, coat hooks, grab handles above each door, fabric headliner, fiber coated interior pillars, thick cut pile carpeting and carpeted floor mats. The driver's seat is 10-way powered and the passenger's seat is 8-way powered. There are five manually adjustable headrests, and front seat mounted armrests for driver and passenger. The front seats can be reclined to form a semi-flat area, and the rear 40/20/40 split seats feature recline and fold down. The pull down rear center armrest features dual cupholders and a lighted storage box. An auto-retracting tonneau cover in the rear cargo area is synchronized to retract when the rear liftgate is opened.

The electro-luminescent instrument cluster is straight-ahead and easy to see and understand with a big 140 mph speedometer, a big 200 KW gauge, and a split gauge for fuel and engine coolant temperature. Bright LED readouts warn of any problems. All buttons, dials and switches are within easy reach and fully illuminated. Interior luxury and convenience features include a Touch Screen DVD navigation system with a seven-inch screen including Bluetooth and voice activation. The screen also reverts to a TV screen showing what is behind you as you back up. The screen also includes a multi-information display that incorporates climate controls, energy monitor and fuel consumption displays. Other features include Adaptive Cruise Control where you set the distance of the vehicle in front of you before the system slows the RX400h down for you, two-person memory for the steering wheel, driver's seat and outside mirror settings, steering wheel controls for audio, multi-information display, cruise control, voice recognition and telephone. The electric sunroof is one-touch tilt/slide, and the automatic dual-zone climate control comes with a dust particle and deodorizing interior air filter. Also featured are rear air-conditioning ducts, defogger with timer, and illuminated entry with lighted sill plates, door handles and foot wells. Helping you even further entering or exiting the vehicle is a courtesy light mounted on the doors, with an illuminated glove box, center console and front cupholders. There are strong dual map lamps and a cargo lamp in the rear. You'll never have to fumble around at night to locate almost anything inside. There are two 12-volt power outlets up front and one in the center console, and one in the cargo area. All four windows are power one-touch up or down. The power door locks feature an anti-lock out feature. The fuel door and rear power lightgate can be opened from inside. My test Lexus RX400h came with all the options including the superb Mark Levinson 210 watt, premium AM-FM/CD audio system with eleven speakers, adjustable front seat heaters and DVD rear seat entertainment system. The all-new 2006 Lexus RX400h is as complete as you can get in a luxury sport utility vehicle brisling with the latest in automotive high technology, luxury and creature comforts. It is also one of the safest to be driving in.

Standard safety systems include advanced airbag system (SRS) for the driver and front passenger that includes driver's dual-stage airbag that uses crash severity and seat track position to choose one of three possible deployment speeds, front passenger dual-stage airbag uses weight and crash severity to choose one of two deployment speed. The airbag will not deploy for passengers under 68.3lbs. or when child seat is detected. Large front seat-mounted side airbags are designed to protect the torso, abdomen and pelvis. Front and rear side-curtain shield airbags have a rollover sensor. Driver's side knee airbag, high strength cabin reinforcements result in minimal post-crash intrusion and no fuel leakage. Force limiting seatbelt pretensioners for the driver's and front passenger's seats, three-point seatbelts for all rear seating positions keep everyone held tight. To protect children riding in the rear are top tether anchors (three) and a child-locking rear door keeping them safe. Ten seconds after starting the vehicle, a flashing seat belt warning light and chime is sounded reminding both driver and front passenger to buckle up. Soft upper interior trim, separate head rests for each seating position, side impact door beams, front/rear crush zones, brake pedal regression prevention mechanism helps to reduce leg injuries in head-on impacts. Also adding to safety is a collision fuel cut-off switch and Daytime Running Lights. Security systems to keep your new Lexus RX400h safe is a vehicle theft deterrent system, multi-function in-key remote with engine immobilizer and remote window 'down' feature, entry system with lock, two-stage unlock, trunk open and 'panic' features, volume-adjustable confirmation tone and rolling code technology. Remote activated/key linked illuminated entry, dome light and ignition key cylinder ring illumination are activated when the doors are unlocked for up to 15sec. or until door is reopened. That's a lot of information but the all-new 2006 Lexus RX400h is no regular luxury sport utility vehicle. It comes with every imaginable convenience, luxury and safety feature, and the world's first application of a powerful hybrid gas-electric powerplant that is both environmentally friendly, and stretches your gas mileage like a compact sedan. If you can afford the $50,000.00 price tag it is the 'got-to-have' ride. © All text and photos by Harvey Schwartz

For more information on Lexus products, go to More photos from Harvey Schwartz can be found at SPECIFICATIONS Name of vehicle: 2006 Lexus RX400h Price of vehicle: Around $50,000.00 Engine type: Gasoline driven 3.3 liter, aluminum block/heads, DOHC, V6 Horsepower: 208 at 5,600rpm Torque: 212lb.ft. at 4,400rpm Electric Motors Motor generator I (MG1) Function-generator, engine starter, transmission ratio control Type-permanent magnet motor Max voltage-AC 650V Motor Generator 2 (MG2) Function-drivers front wheels, regeneration during braking Type-permanent magnet motor Max voltage - AC 650V Max output - 165 hp (123kw) at 4,500 rpm Max torque - 247 lb.ft. at 0-1,500 rpm Motor Generator Rear (MGR) Function-drives rear wheels, regeneration during braking Type-permanent magnet motor Max voltage-AC 650V Max output - 68 hp (50kw) at 4,610-5,120 rpm Max torque - 96 lb.ft. at 0-610 rpm Drive configuration: Front engine/two electric drive motors/all-wheel drive Horsepower: 270 combined horsepower at 5,600rpm Torque: 290lb.ft. combined of torque at 4,400 rpm Transmission type: Electronically controlled continuously variable transmission (ECVT) with planetary gear unit for gear reduction and power splitting, electronic all-wheel drive control system. Front suspension: MacPherson struts, coil springs, gas-charged shocks, stabilizer bar Rear suspension: Dual link strut, coil springs, gas-charged shocks, stabilizer bar Wheels/tires: 18x7 graphite polished aluminum alloy wheels and 235/55R-18 all-season performance tires, full size spare with aluminum alloy wheel Brakes: Front: 12.6-inch vented disc with dual piston calipers Rear: 11.3-inch solid disc with single piston calipers Electronically Controlled Brake system (ECB) with regenerative control and incorporating ABS, EBD, BA, and Vehicle Dynamics Integrated Management system (VDIM) Overall length: 187.2 inches Overall width: 72.6 inches Overall height: 66.4 inches without roof rack Curb weight: 4,365 pounds EPA mileage: 25 mpg/city, 35 mpg/highway 0-60 mph: 6.9 seconds

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