2010 Lexus RX 450h Bottom Line

By  Marty Padgett, Executive EditorMarty Padgett

The 2010 Lexus RX 450h carries a torch—for advanced hybrid technology, for better fuel economy, but mostly, for the luxurious look and feel of the previous model. It's so close in shape to the outgoing RX 400h, it's hard for observers to tell the difference from the previous crossover hybrid's shape.

There are subtle differences, though, from the old version to the new 2010 Lexus RX 450h. The details are finessed—smaller headlamps, skinnier rear glass, a more pinched appearance from the side. The overall appearance is somewhat less imposing than before, but still handsome. The cockpit suffers a bit; the new shapes and textures of the dash, particularly the center console, are a little less rich and inviting, and less wood trim covers the dash. It can be difficult to tell the hybrid RX 450h from the gas-only RX 350, too; differences amount to blue-lit gauges, a tinted grille, and a tweaked front bumper, as well as small hybrid logos and optional 19-inch wheels.

Beneath the hood, the 2010 RX 450h is completely different, of course. Instead of a conventional V-6 engine, there's a 3.5-liter V-6 coupled to Toyota's Hybrid Synergy Drive, which includes two separate motors (a third on all-wheel-drive versions); a continuously variable transmission instead of a six-speed automatic; and a hefty battery pack under the second-row seat. The combination of gas and electric power, Lexus says, gives the RX 450h fuel economy of 28 mpg city, 26 mpg highway, about 10 percent better than the last RX hybrid. That compares well to the gas-only RX 350's 18 mpg city, but not so well to the RX 350's 24-mpg highway rating. Different driving modes are enabled by new computer controls; there's even a driver-selectable electric-only mode, in which the RX uses only the power stored in its nickel-metal-hydride batteries.

It's easy to see how the already aloof RX feels even more distant with the hybrid system's added weight and continuously variable transmission; the electric power steering common to both the RX 350 and RX 450h lacks road feel, but at least the newer, larger brake rotors seem more sporting. As in the gas-only RX, the Lexus RX 450h's best talents are in providing a smooth, quiet ride.

The raft of improvements shines also on the RX 450h's interior space. A redesigned rear suspension gives it about 5 percent more cargo room behind the second-row seats. Drivers and passengers continue to enjoy good head-, leg-, and shoulder room, so long as there are only four involved. Adding a third passenger to the second row of seats tightens things up considerably. No third-row seat is offered. The impression of quality is largely carried over from earlier models, but the redesigned instrument panel has swapped some of its high-end look for swoopy, silver-painted plastic. Too, there's more drivetrain noise and vibration in the RX 450h than before.

The 2010 Lexus RX skips nothing in the safety department. It contains 10 airbags in all, including curtain airbags and side bags for the rear seats, as well as standard anti-lock brakes, stability and traction control, and a hill-holder feature. The RX 450h's safety controls also integrate the operation of the stability and traction control for more predictable handling. For 2010, Lexus offers a Pre-Collision System, which uses radar sensors to detect a possible impact, then to ready the brakes and seatbelts for an imminent crash; adaptive lighting; and automatic high beams. TheCarConnection.com will revisit the RX 450h's safety ratings when the NHTSA and IIHS perform their safety tests.

Outfitted with a host of upscale gear, the 2010 Lexus RX 450h leaves some equipment on the options list for the truly extravagant. All hybrid RXs have a CD player, Bluetooth connectivity, dual-zone climate control, and 10-way power front seats. Options include leather seating, a side-view monitor, USB connectivity for MP3 players, a Mark Levinson sound system, a hard-drive navigation system, XMNavTraffic, a rear-seat entertainment system, ventilated front seats, remote start, and a sport-minded suspension.

A touchy new subject with the Lexus RX is its new Remote Touch controller. Like the haptic systems from BMW (iDrive) and Audi (MMI), Remote Touch uses a single device to consolidate climate, entertainment, and navigation functions inside the cabin. The Lexus controller, though, resembles and acts like a mouse—unlike the click-wheel systems from the Germans. It's a more logical operation, but it's still electronic intervention where buttons and switches would be easier. A head-up display is optional, and it adds to the gee-whizzery that can turn the RX into an eerily fast driving simulator.

The most desirable feature of the 2010 Lexus RX 450h, aside from improved fuel economy, might be the Lexus ownership experience. The crossover might not be exciting to drive, and some may not see the mileage dividends without changing their driving style—but every Lexus owner is treated exceptionally well.