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2007 Lexus RX 400h Review

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2007 Lexus RX400h
2007 Lexus RX 400h
The Lexus RX400h debuted early in model year 2006 as the premium model of the RX lineup, in an interesting, and unusual, part-time all-wheel drive form. While a 3.3-liter, 208-horsepower gasoline engine and 167-horsepower electric motor drove the front wheels, the rear wheels were electrically-powered only, by a 68-horsepower motor. Maximum power was rated as 268, said by Lexus to be equivalent to a 4.0-liter V8, hence the RX 400h nameplate.

The market for a high-tech luxury crossover SUV is healthy, as nearly 30,000 examples were sold in its first full year on the market. Many cars get standard equipment and trim package changes for their second year, but the RX hybrid's changes may seem unusual. It's apparently been decontented. The RX 400h line goes from one fully-equipped premium model to a lineup more closely aligned with the gasoline-only RX 350 in standard and optional equipment levels. There is a new front-wheel drive only model, and many features previously standard are now optional. The result - lower prices, and a lineup that can appeal to more people. In the Toyota/Lexus world, hybrids are not only for high-tech early adopters, they will eventually be mainstream vehicles for everyone. The RX 400h model realignment should help expand its appeal.

I just spent a week with a 2007 RX 400h. Press fleet spec being what it usually is, it was not an "entry-level" front-wheel drive model, but a well-equipped all-wheel drive model. Still, both the base and as-delivered prices were significantly less than those of the 2006 model I drove a year ago, with negligible negative impact on its luxury level. As always, it was exceptionally quiet, smooth, and comfortable, with no shortage of power when needed. In steady-state, light-throttle operation, it often ran under pure electric power at speeds up to 35mph, at which time it was uncannily quiet. At 24 mpg in a week with plenty of high-speed freeway driving - not the best environment for hybrid fuel economy - it was still more economical than any similarly-sized gasoline SUV. Hybrids work well, and for more than small commuter cars.

APPEARANCE: Differences between the hybrid RX 400h and the regular RX 350 are minimal on the outside. Look for a slightly different grille, and a small extra opening in the front bumper. It also has front foglamps and LED taillights. New badging with blue highlights starts a Lexus trend.

COMFORT: As outside, interior differences between the gasoline and hybrid versions of the RX are minimal, especially with the standard equipment realignments. The battery pack is located under the rear seat, and all that can be seen are vents in the solid underseat area. Leather upholstery, a roof rack, a power tilt and telescope steering wheel, a moonroof, and memory settings for the driver's seat, steering wheel, and outside mirrors are now optional, and make up the Premium Package with which my test vehicle was equipped. The touch-screen navigation system is also now an option, included here. The front passenger seat now has standard power lumbar support, in addition to the usual power adjustability. As equipped, the RX h is a wonderfully comfortable and well-equipped luxury vehicle; in standard trim it wouldn't be all that less luxurious. Seat comfort, front and rear, is first-rate, as is cargo space.

SAFETY: Besides the usual complement of front, front side, and side curtain airbags, and a driver-side knee airbag, the RX400h has Lexus's Vehicle Dynamics Integrated Management (VDIM) system. VDIM through electronically-controlled brakes, integrates braking, traction control, and Vehicle Stability Control (VSC) system functions with the electronic throttle control, electric power steering, and regenerative braking systems to improve driver control of the vehicle. A tire-pressure monitoring system is new this year.

RIDE AND HANDLING: As with the RX 350, don't look for rugged off-road ability in the RX 400h, but that hasn't bothered RX buyers, as the gas versions have been best-sellers for Lexus. The fully-independent MacPherson strut front, dual-link strut rear suspension is tuned a little more firmly than that of the RX 350, but it still emphasizes luxury comfort over sportiness. Add the quiet of the drivetrain, and the RX 400h is a very relaxing vehicle in which to cover distance.

PERFORMANCE: Any assumptions that a hybrid system is appropriate only for a small, high-mileage ``economy car'' can be laid to rest with one short drive in an RX400h. If power is required, simply press the accelerator to the floor and power is delivered, strongly. At that time, the 3.3-liter twincam, 24-valve V6 engine audibly makes its presence known, but most of the time it is nearly as silent as the electric motors. Other than when the gasoline engine comes on strong when acceleration is needed at highway speeds, or when torque from the electric motors kicks in at lower speeds, it's nearly impossible to tell where the power is coming from without sneaking a peek at the display in the instrument panel, and operation of the rear motor is completely transparent. The Hybrid Synergy Drive system used in the RX400h is similar to that in the Prius, but like in the RX's cousin Toyota Highlander Hybrid, modified for a larger, more powerful engine and front and (if so equipped) rear motor-generators.

The engine makes a maximum of 208 horsepower at 5600 rpm, with 212 lb-ft of torque at 4400 rpm. The front motor makes 167 horsepower at 5600 rpm and 247 lb-ft of torque from zero to 1500 rpm - just the ticket for fast acceleration when needed. They are coupled through a planetary gear continuously-variable transmission, which is controlled by computers and motor-generator 1, which is also the starter motor. A second motor, with 68 hp from 4610 through 5120 rpm and 96 lb-ft of torque from zero to 610 rpm, runs the rear wheels when the control computer decides extra rear traction is needed. Around town, the RX operates electrically as much as possible, with the gas engine stopping when the car is stopped and assisting the electric motor(s) when moving. On the highway, the motors assist the engine. Note that the engine and motors never develop maximum power at the same time, but still, maximum system horsepower is listed at 268, not bad at all. Computers control the show, and it works smoothly and efficiently. If the real-world 24 mpg I averaged was less than the EPA rating, it was still better than anything from a similarly-sized internal combustion vehicle.

CONCLUSIONS:The Lexus RX 400h shows that luxury and utility can have a low environmental impact, and changes to its standard and optional equipment levels for 2007 should increase its appeal.

SPECIFICATIONS - 2007 Lexus RX400h
Base Price			$ 42,580
Price As Tested			$ 47,855
Engine Type			dual overhead cam,
				 24-valve aluminum alloy V6
Engine Size			3.3 liters / 201 cu. in.
Horsepower			208 @ 5600 rpm
Torque (lb-ft)			212 @ 4400 rpm
Electric motors			permanent magnet, 650VAC
Motor-Generator #2		drives front wheels
Horsepower			167 @ 4500 rpm
Torque	(lb-ft)			247 @ 0-1500 rpm
Motor-Generator Rear		drives rear wheels
Horsepower			68 @ 4610-5120 rpm
Torque				96 @ 0-610 rpm
Battery pack			Sealed NiMH, 288V, 45kW
Transmission			computer-controlled continuously variable
Maximum combined horsepower	268
Wheelbase / Length		106.9 in. / 187.2 in.
Curb Weight			4365 lbs.
Pounds Per Horsepower		16.3
Fuel Capacity			17.2 gal.
Fuel Requirement		91 octane unleaded premium recommended,
				87 octane unleaded regular gasoline acceptable
Tires				225/60 SR17
Brakes, front/rear		vented disc / solid disc,
				 ABS and regenerative braking standard
Suspension, front/rear		independent MacPherson strut/
				 independent dual-link strut
Ground clearance		7.1 inches
Drivetrain			transverse front engine and motor,
				 automatic on-demand single-range
				 four-wheel drive by rear motor

EPA Fuel Economy - miles per gallon
    city / highway / observed		31 / 27 / 24
0 to 60 mph				7.3  sec
Towing capacity				3,500 lbs.

Two-level heated front seats			$  665
Navigation system - includes:
  generation 5 navigation system with rear camera, 
  Bluetooth, voice activation, compass, energy and
  consumption monitors				$ 2,650
Premium package - includes:
  leather-trimmed interior, power tilt/telescopic
  steering wheel with memory, memory driver's seat
  and outside mirrors, illuminated entry system,
  one-touch moonroof, roof rack			$ 1,245
Delivery charge					$   715