RX Just What the Doctor Ordered

Yes, Toyota Motor Corp. will Launch an all-new Lexus RX cross/utility vehicle, and yes it looks a lot like the old one.

Lexus officials say RX owners, the most loyal of all Lexus connoisseurs, like the way their vehicle looks and don't want a radical styling change, thank you very much.

Styling aside, the new '10 Lexus RX 350 and 450h hybrid are fine vehicles, with confident handling characteristics and, in the case of the RX 450h, near class-leading power that should push the CUV away from the hockey-mom, soft-roader image it's held for so long.

The RX series, arriving in February, is a bona fide fuel sipper and gets a plush new interior and impressive technology.

Toyota engineers have tightened the suspension and fixed the over-assisted steering, two major quibbles with the current RX, to match most competitors, which tend to be sporty instead of soft.

In the five-plus years since the current RX launched in 2003, the bar has been raised for luxury CUVs.

Honda Motor Co. Ltd.'s Acura MDX, Nissan Motor Co. Ltd.'s Infiniti FX and Daimler AG's Mercedes-Benz M-Class have been revised; and new entrants such as Ford Motor Co.'s Lincoln MKX, Volkswagen AG's Touareg and Audi Q7 have arrived in recent years, aiming at Lexus' dominance in the sector.

The RX has been the No.1 selling luxury CUV for five years, according to Ward's data. But sales have slipped as the CUV aged in the face of newcomers with standout performance and better interiors (MDX, FX, BMW X5 and M-Class).

A spin in the outgoing Lexus RX 400h reminds how dreadful the interior had become, with lots of shiny hard plastics and, dinosaur of all dinosaurs, an ignition that started with a conventional key.

The new interior, with a contemporary push-button starter, is vastly improved. It offers better materials and, finally, new switchgear, such as the updated side-mirror control buttons.

The new RX 450h also demonstrates Toyota's dramatic improvements to deaden the whirring from the electric motor and mitigate throttle vibrations normally associated with hybrid-electric vehicles.

The layout of the hybrid system remains unchanged from the first-generation RX, with the nickel-metal hydride battery — albeit lighter and more compact — still housed underneath the rear seats.

Several fuel-sipping measures have been instituted with the RX 450h, such as a new Atkinson-cycle 3.5L V-6, which replaces the 3.3L Otto-cycle V-6 of the current 400h.

Others include a cooled exhaust gas recirculation system, which circulates inert exhaust gasses through a coolant heat-exchanger, cools them, and then introduces some into the intake manifold; and an exhaust heat recovery system, allowing the engine to shut off more often.

Also, a new hybrid power control inverter is smaller in weight and volume, by 17.6 lbs. (8 kg) and 0.42 cu.-ft. (11.8L).

These measures improve the RX 450h's fuel efficiency compared with the outgoing RX 400h's hybrid system by 8%, Lexus says, despite a 27-hp jump that puts the combined output of the 3.5L V-6 and electric motor at 295 hp, just 5 hp below the class-leading 303-hp made by the Infiniti FX's 3.5L V-6.

In a Napa Valley drive, the '10 RX 450h, in front-wheel-drive and all-wheel-drive configurations, easily achieves at least 30 mpg (7.8 L/100 km) on average.

In a loop that meanders through a vineyard, the FWD RX 450h manages 31.2 mpg (7.5 L/100 km), while the heavier AWD RX 450h actually does better: 32.8 mpg (7.2 L/100 km).

Lexus says historically just 20% of all RXs sold have been hybrids. But when high fuel prices return to the U.S., the 450h will be positioned to take a bigger piece of the RX pie.

The non-hybrid RX 350 was thrifty too, with the FWD model averaging a 4-cyl.-like 24.6 mpg (9.6 L/100 km) in mostly city driving. Ward's averaged 25 mpg (9.4 L/100 km) under similar conditions in the new FWD Toyota Venza CUV powered by a 2.7L I-4.

The RX 350 fuel-economy figure is even more impressive considering the curb weight difference between the 4,340-lb. (1,969-kg) FWD RX 350 and the 3,760-lb. (1,706-kg) FWD Venza.

Both versions of the '10 RX get a redesigned MacPherson front strut suspension and a new, compact double-wishbone independent rear, replacing the independent strut configuration.

The RX 350 gets just 5 more hp and 4 more lb.-ft. (5.4 Nm) of torque in its newest iteration, as Toyota retains the '09 RX 350's 2GR-FE 3.5L V-6, with tweaks.

A new 6-speed automatic transmission replaces the outgoing RX 350's 5-speed auto. A lower first gear improves launch time, while closer third-sixth gear ratios boost fuel economy, Lexus says.

In a first for Lexus, active torque control all-wheel drive is offered in both the RX 350 and 450h. An electronic rear coupler replaces a center differential, and overall the unit is 66 lbs. (16 kg) lighter than the system it replaces.

The on-demand system, disengaging at speeds above 25 mph (40 km/h) or during braking, can apportion torque front-to-rear 100:0 or to a maximum 55:45.

All manner of techno-wizardry is available in the new RX interior, most notably a new Remote Touch controller that operates the navigation/infotainment system, replacing a touch-screen.

Protruding from the center console is a hump with a flat square knob at the top. The joystick-like knob moves left-to-right and up-and-down, like the computer mouse that inspired its design.

After positioning a pointer with the knob, a thumb-operable button on the lower left of the hump can be pressed to make a selection.

But the thumb button is not very intuitive. Pushing down on the knob seems like a more logical movement for a generation now familiar with computer mice. But Lexus officials say bumpy roads could lead to an erroneous selection.

Also new for the RX is an improved voice-activated navigation system, now with casual-speech technology.

During our test drive, the system recognized the statement, “It's too cold in here,” and boosted the temperature. The speech software, provided by VoiceBox Technologies, mostly ignores “ums” and “uhs,” although one “um” led it to ask if we wanted to go “home.”

The '10 Lexus RX 350 goes on sale in February, the RX 450h around May.

Lexus should be able to retain the luxury CUV crown with its new RX, especially with the impressive fuel economy of the RX 450h.

But a less-expensive Toyota Venza could pull buyers away, given the sagging economy and lackluster luxury sector in the U.S.

'10 Lexus RX 350

Vehicle type: Front-engine, front-wheel-drive, 4-door cross/utility vehicle

Engine: DOHC 3.5L V-6 with aluminum block/aluminum heads

Power (SAE net): 275 hp @ 6,200 rpm

Torque: 257 lb.-ft. (348 Nm) @ 4,700 rpm

Compression ratio: 10.8:1

Bore × stroke (mm): 94 × 83

Transmission: 6-speed automatic

Wheelbase: 107.9 ins. (274 cm)

Overall length: 187.8 ins. (477 cm)

Overall width: 74.2 ins. (188 cm)

Overall height: 66.3 ins. (168 cm)

Curb weight: 4,340 lbs. (1,969 kg)

Base price range: TBD

EPA mileage: 18/25 city/hwy (13.1-9.4 L/100 km)

Market competition: Mercedes M-Class, Acura MDX, BMW X5, Infiniti FX, Lincoln MKX