2010 Lexus RX 450h review: 2010 Lexus RX 450h

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2010 Lexus RX 450h

7.7

2010 Lexus RX 450h

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The Good

The 2010 Lexus RX 450h enhances its luxury ride and cabin with a hybrid power train that achieves fuel economy unheard of for an SUV. Both navigation and phone systems offer advanced features.

The Bad

The navigation system requires too many button pushes to reroute around traffic problems, and the audio system doesn't mute for route guidance instructions.

The Bottom Line

Lexus' new cabin tech suite helps the 2010 RX 450h keep on par with other car tech leaders, but the hybrid power train gives it a greater edge, delivering superior fuel economy and low emissions.

Remember that Seinfeld episode where George Costanza said, "I would drape myself in velvet if it were socially acceptable?" Well, sitting in the 2010 Lexus RX 450h is like being draped in velvet, and, with the economical hybrid drivetrain, it is socially responsible.

Lexus vehicles show a level of luxury unequaled in today's market by all except cars costing hundreds of thousands of dollars. Run your fingertips along the soft headliner, open and close the whisper-quiet power windows, and you will see what we mean.

And it doesn't hurt that the 2010 Lexus RX 450h is one of the more technically advanced cars available today. This iteration of Lexus' hybrid, five-passenger SUV gets a new cabin tech package with a hard-drive-based navigation system, iPod integration, Bluetooth stereo streaming, and voice command that lets you dial contacts by name. The hybrid power train moves the RX 450h along under electric power only at slow speeds, mixing in drive from the 3.5-liter V-6 for acceleration or speeds above 30 mph.

Hybrid efficiency
The 2010 RX 450h and nonhybrid RX 350 share body and cabin tech, but the RX 450h's hybrid drivetrain makes a world of difference. When we had the 2010 RX 350 in a few weeks ago, we weren't terribly impressed by the engine and transmission. The hybrid power train in the RX 450h makes this vehicle more powerful while at the same time getting much better fuel economy. If anything proves the value of a hybrid, it's that comparison.

Surrounded in plastic, this engine is a little too complicated for the shade-tree mechanic of yesteryear.

Although the engine size is the same between both SUVs, the RX 450h uses an Atkinson cycle for its intake and exhaust strokes, gaining efficiency at the expense of torque. But that's OK, as the hybrid system's 167-horsepower electric motor punches in the needed twist when you step on the accelerator. Lexus claims the RX 450h's hybrid system gives the power of a V-8 and the fuel economy of a four cylinder--a not entirely inaccurate statement.

Total power from engine and electric motor is rated at 295 horsepower, a little short of a V-8, while fuel economy gets an EPA-rated 32 mpg city and 28 mpg highway. In our mixed city, freeway, and mountain driving we achieved 27.7 mpg, a figure that many four cylinder cars would have trouble hitting.

Lexus improved its hybrid system for the 2010 model year, using lighter battery, motor, and control module components. At the heart of the system is a planetary gearset, mixing power from the engine and electric motors and relaying it to the front wheels. The RX 450h is also available as an all-wheel-drive vehicle, where it gets an extra electric motor for the rear wheels.

Through the city
In typical full hybrid fashion, the RX 450h glides forward under electric power when you put it in drive. All but the lightest pressure on the accelerator kicks in the gas engine for the extra power the car needs to get up to speed. We like the idea of keeping it running under electric power for as long as possible--it's always pleasing to watch the fuel economy climb--but in city driving it's not really practical. To avoid blocking traffic and frustrated honking from people behind us, we gave it extra throttle when the lights turned green, kicking in the gas engine to get something more than a sedate push. You can drive more economically than we did, but be ready for other drivers to give you the old somersaulting fowl gesture as they pass by.

The hybrid system is ready and willing to propel the car under electric power.

The RX 450h uses an electric power steering module, but, as in the new RX 350, Lexus tuned it for a little more road feedback than in the previous generation. Where the wheel in the earlier RX could be turned with one finger, the new one gives a satisfying resistance, making you feel like you're controlling the car. But this resistance didn't keep the RX 450h from being very drivable in the crowded urban streets of San Francisco. In fact, with the hybrid system keeping the engine quiet at stop lights, it seemed like an excellent urban vehicle.

Outside of the city, the 2010 RX 450h proved a pampering capsule on the open road, its suspension delivering a smooth ride over all manner of rough pavement. At freeway speeds, the gas engine generally stays on, ready to provide passing acceleration when needed, and explaining why the city fuel economy is better than the highway rating.

We wouldn't normally test out an SUV like we would a sports car, and certainly not a hybrid model, but we did find ourselves late for a meeting, on the wrong side of a coastal mountain range, and so pushed the RX 450h hard over winding roads. Well, not too hard, but enough to get the traction control to quell our speed in a few turns in that intrusive fashion that Lexus road-holding electronics use.

This shifter controls a virtual gearbox, a computer-controlled planetary gearset with continuously variable ratios.

Ignoring good fuel economy practices, we repeatedly punched the accelerator coming out of turns, getting a strong result from the car as it picked up speed. In the turns, the RX 450h didn't wallow particularly, its suspension trying to put it back on an even keel after inertial lean attempted to pull it away from the apex. In all, it showed itself game for this type of driving, it not entirely capable. Understeer was evident entering the turns, and the rear wheels were more obedient followers than active participants.

The shifter does have an S on it, along with a plus and minus for manual shifting. But there are no fixed gears in this transmission. Rather, it is an electronically controlled continuously variable virtual gearbox. If you put it in manual mode, you are merely shifting through virtual shift points, a computer's idea of where a gear should be. Put it in Sport, and it merely limits the top virtual gear to fourth. These shift points are useful to control the vehicle's speed in slippery conditions, but don't have anything to do with sport.

Remote control
Near the shifter, mounted on the console, is an odd-looking growth, the likes of which haven't previously been seen in cars. Where Lexus used to rely on touch screens to control the cabin tech, the desirability for antiglare purposes of recessing the LCD deep in the dash led the company to develop the Remote Touch controller. This new controller is a joystick that moves a pointer on the car's LCD. If you've used a mouse, Remote Touch will be second nature. The ergonomic joystick and mount fits easily into your hand, with an enter button on the side of the mount.

The Remote Touch controller moves this finger-shaped cursor over the LCD.

At the front of the mount are buttons for the main menu and quick access to the navigation system map. We would also have liked quick access buttons for audio and phone systems. But we found it easy to quickly select menu items with the joystick--it's faster than even Infiniti's cabin controller, which has been our favorite for usability. The new Lexus controller delivers haptic feedback as you move its cursor over menu items, making it easy to use while paying attention to the road. And the amount of feedback is adjustable.

The new navigation system stores its maps on a hard drive, although Lexus didn't do much to improve the maps themselves. The RX 450h only offers 2D maps, as opposed to the 3D maps becoming common with other automakers. But these maps show good resolution and are overlaid with traffic information, including traffic flow in red, amber, or green, as well as specific incidents.

This system wasn't entirely consistent about helping us detour around traffic problems on a programmed route. We had the navigation system set for dynamic routing around traffic incidents, but still had to go through about three menus to make it recalculate our route after it announced slow traffic on the road ahead in some cases. At another time it actually did bring up a proactive warning about a traffic problem ahead, and provided easier access to calculating a detour.

Route guidance itself works well, with graphics to show upcoming turns and text-to-speech (the system reads out the names of upcoming streets). One annoyance we had with this navigation system is that, when giving voice guidance, it didn't mute the stereo. We could barely hear the navigation instructions when playing music at moderate volume, and not at all when playing loud music.

Entertaining in car
The 2010 RX 450h offers most of the music sources we've come to expect from a modern system. Along with satellite radio, there is an MP3 compatible in-dash six-CD changer, a USB port that can also accept an iPod cable, an auxiliary input, and Bluetooth audio streaming. The only things it lacks are HD radio and the ability to rip CDs to the navigation system's hard drive. The CD changer seemed very slow to read discs, but that might be more our perception when comparing it with the speed of iPod access.

The Remote Touch controller does its job well for selecting music. USB drives and MP3 CDs are just shown in file and folder formats, while iPod integration lets you select music by album, artist, and genre. Another annoyance: when viewing the song detail screen, to see which songs are playing on a satellite radio station, for example, the LCD automatically switched back to the map screen after about 30 seconds.

This RX 450h was loaded with all the cabin tech options, including the top-of-the-line Mark Levinson audio system and rear-seat entertainment system. We like how the entertainment system's LCDs are mounted to the backs of the front seats, meaning they don't change positions with the headrests and there is no screen dropping down from the ceiling to obscure the rearview mirror.

Rear-seat video monitors are conveniently mounted to the backs of the front seats.

For the RX, Lexus only offers the Mark Levinson audio system in conjunction with the rear entertainment system. The other option packages include the lesser, but still premium, sound system we heard in the RX 350. Where the Mark Levinson system uses 15 speakers, the premium system only has 12. However, we didn't notice a real difference in the audio quality between these two systems. The Mark Levinson system, with its 330-watt amp and 7.1-channel surround sound, seems suited for movie viewing, explaining its inclusion with the rear-seat video package.

Although the audio system didn't mute for navigation guidance prompts, it did for the Bluetooth phone system. This system is the same one we saw in the RX 350, and it does everything we could ask. It paired easily to an iPhone and let us upload the phone's contact list to the car. Contacts were available on the LCD, using the Remote Touch controller, but, more conveniently, each contact can be dialed by name with the car's voice command system.

In sum
The 2010 Lexus RX 450h offers a lot to keep us happy. If it isn't placing calls by saying the name of the person to whom we want to talk, it's modulating the accelerator to maximize electric drive and fuel economy. And it doesn't hurt to be sitting in such a comfortable environment. This RX sports one of the highest tech power trains available, and the results show in the excellent fuel economy. And while the suspension isn't particularly advanced, it does deliver an appropriately luxurious ride.

The cabin tech offerings excel in the basics--navigation, phone, and audio systems. But where the RX 450h lacks is useful driver-aid technology. It does have a rearview camera, but it's a simple bumper view, with no overlay lines. The electronics interface design isn't perfect--we found a few areas where it could be refined. But we do like the overall design of the car. Although an SUV, it remains a manageable size. Most people can see over the roof when standing next to it.

Spec box