The term "soccer mom" defined perhaps too well how many mothers lived the child-rearing parts of their lives in the 1990s. They hated that researchers could predict their voting and buying patterns just because they drove slab-sided Dodge Caravans and repair-prone Ford Windstars. That—and clunky design—helped dampen enthusiasm for the minivan.

Fast forward 15 years, add a slew of energy-saving technology, and you've got a near-perfect minivan-replacement vehicle for parents who chauffeurs kids to lacrosse matches: the Lexus RX 400h hybrid-drive SUV. The superb audio and Bluetooth phone technology make traffic jams en route to the office more bearable, too.

In the RX 400h, Lexus mated a V6 gasoline engine with a continuously variable transmission and placed a bank of nickel metal hydride batteries under the back seat. It also put electric-drive motors both front and rear for great fuel economy in town, reasonable acceleration, passable fuel economy on the highway, and as-needed all-wheel drive. If the majority of your driving is done around town and you need some (but not a lot of) cargo space, the RX 400h could be ideal. Just realize you'll spend $50,000 to get good gas mileage.

As with other hybrids, the motors that help drive the vehicle also work as generators under deceleration, resisting the energy from the forward motion and converting it to electricity. More than half the kinetic (moving) energy is recaptured in the NiMH batteries. As a side benefit, regeneration saves wear and tear on the brakes; and the energy is available the next time you step on the throttle. On the interstate, there's very little stop and go, which is why fuel economy with hybrids is lower on the EPA's highway rating. The RX 400h is rated at 31 mpg in the city, 27 mpg on the highway for the 2007 model; the 2008 will be 1 mpg to 2 mpg lower because of revised EPA testing standards, which should be more realistic.

By installing an electric drive motor at the rear wheels, Lexus provides all-wheel-drive capabilities without the need for a bulky driveshaft. Under heavy acceleration or on slippery roads especially, the rear propulsion kicks in. There's also an electric motor up front, which is important for regenerating the most energy, since more weight is on the front wheels under braking. That's why the nose of a car pitches down when you step on the brakes and goes up when you accelerate.

Having electric propulsion up front as well allows for one of the RX 400h's neatest impress-the-neighbors tricks: When you start the engine, there's no sound, vibration or exhaust smoke, only a Ready light that comes on after a second or two. Then the RX 400h motors off silently under electric power. If you avoid tromping the throttle or turning on the air conditioner, you can get up to about 20 mph before the gasoline engine kicks in.

Long-time hybrid users may have adapted, but I'm still uncertain about the real-world impact (so to speak) of silent vehicles on kids playing in the driveway or the none-too-bright family pet when you back noiselessly out of the garage. You can order a backup camera as part of the $2,650 navigation package, but there's no backup sonar, which I believe can be more important than the camera for proactively detecting objects in your path.

I also fear new owners may not realize a hybrid is in gear when they pull into a convenience store or gas station and begin to step out. There is a warming chime, but it's polite and no more urgent than the chime for an unbuckled seat belt or still-on headlights. Obviously, RX 400h owners would be paying stiffer insurance premiums if roll-away incidents happened a lot, but I think Lexus and others need to think more about this downside of hybrid technology before people get run over.

In years past I've been a fan of the Denso navigation system used by Lexus and its sibling, Toyota. But the feeling is fading. This nav system is called Generation 5, but the voice input makes it feel like Generation Behind. It's fairly simple to use (for a navigation system), with a touch-screen interface and largish buttons next to the LCD. The Nuance-based voice input recognizes voices well, so long as you use the preset phrases.

But there's a maddening pause between pressing the Voice button on the wood-and-leather steering wheel (a $380 extra on my test car) and the time that it's ready for your command. You're greeted with phrases such as, "At the beep, please say a command [maddening pause … beep]," or, "At the beep, please say the state name [pause] …. please say the city name [pause]." Lexus is stalling for time as the system spools up to speed. This suggests the car needs a faster microprocessor, a bigger cache of phrases stored in memory, or very patient drivers.

The $2,650 navigation package also includes the backup camera, energy and consumption monitors, and Bluetooth. Each feature is problematic in minor ways.

The view provided by the backup camera is dim at night. Other automakers have more sensitive cameras or brighter backup lights; on this Lexus, you need to back up with your foot on the brake pedal (this improves the view, because of the added illumination of the brake lights). There's also no backing lane overlaid on the display that superimposes the width of the RX 400h as two straight lines (the path straight back) and curved lines (the path as your wheels are now turned). And there's no sonar backup option, which is a valuable adjunct to any backup camera: It's possible to miss seeing an obstacle on the monitor, but you can't avoid hearing the warning ping of sonar.

The energy and consumption monitors paint a dazzling, full-screen portrait of where energy is coming from and going to: the gas engine, storage battery, front electric motor/generator, rear electric motor/generator; and the direction the electricity travels. There's a second screen showing how much energy you've used and regenerated in minute-by-minute increments. It's dazzling for about a week, or when you've got a green-loving neighbor on board. But there's no satisfactory way to tone it down to just a corner of the display, once the initial thrill is gone.

Then there's Bluetooth, which paired fine with a couple of Motorola and LG phones. But given the quirks of the nav system, Lexus shouldn't hold Bluetooth hostage inside a $2,650 options package you may not want. Ideally, Bluetooth should be embedded in all Lexuses as part of the base price, the way Mercedes-Benz is starting to.

Technology aside, the RX 400h is a fine vehicle to drive, either in the hybrid or gasoline-engine version, the RX 350. The batteries are neatly stowed under the back (second-row) seat and cargo floor rather than taking up part of the trunk as on other Toyota/Lexus hybrids. The RX 400h has two rows of seats and a steeply sloped tailgate, so you can carry four or possibly five passengers and a moderate amount of luggage. Four bags of lacrosse gear would fit, but it'd tough carrying the bags for four hockey players. Mamas, don't let your babies grow up to be goalies.

The interior finish is flawless, but what did you expect? It's a Lexus. The RX 400h has a nice rear-entertainment system for kids; the standard audio is fine, and the upgrade audio is superb. You can play MP3 and WMA files, and there's a line-in jack for music players and an optional iPod interface. If you have the navigation system and the LCD, the audio or climate controls momentarily drop down across the top inch of the display to show a new station or temperature setting. It's a nice feature, although Infiniti integrates multiple features better on its LCDs.

The Lexus Web site is simple to use, and you can easily configure your vehicle. Some people use automaker sites so they can avoid salespeople at dealerships for as long as possible, but in the case of Lexus, the dealership experience is about as good as it can be. That's the advantage of setting up a new dealer network in 1990 (when Lexus arrived) with the requirement to treat customers well, rather than take over the corner of Toyota showrooms and put Giant Lexus Sale-A-Thon signs in the window.

One part of the Lexus experience you won't covet, and probably won't take part in, is reading through the 10 manuals and quick start guides that among them total 1,009 pages. That includes 446 pages for the owner's manual and another 296 for the navigation system. The quick-start guide, if you can call it that, runs 56 pages and the navigation quick guide is another 22. My personal belief is that Japanese automakers have an even greater fear of lawsuits than German or American automakers and deal with it by adding more warnings in more places.

I've driven other Lexus and Toyota hybrids before. The Toyota Prius blew me away from the start with its all-round excellence. Some of the Toyota/Lexus SUVs took a while to warm up to, particularly because of the odd noises emanating from the drivetrain, compared with the turbine-like sound of a well-made engine. The most recent RX 400h had its share of off-sounds compared with the sibling 350, which runs on gasoline. Now I find the coarser gasoline engine and occasional grinding sound under acceleration a minor price to pay for getting 30 mph out of a 2-ton vehicle.

A Lexus RX 400h has a base price of $43,275 (for 2007 models) and sells for about $50,000, reasonably equipped. You may or may not want navigation; you'll probably want the premium package ($2,060) that combines technology, such as the steerable xenon headlights; luxury, such as leather trim and a moon roof; and convenience, such as the memory seats and steering wheel.

If you want a mid-size SUV with lots of interior style and great gasoline mileage for an SUV, look at the RX 400h. Even with the hybrid credit disappearing for Toyota and Lexus (the credit was intended to jumpstart each automaker's sales and then go away, not to be an ongoing subsidy for hybrid buyers), I believe your fuel savings will make the hybrid the way to go. Just realize that if it's lower cost of ownership you want, there are plenty of other hybrids, including the Toyota Highlander, that come in for thousands less.

Play Slide Show/All Shots (16)

$43,275.00 - $50,000.00

Lexus advances the state of hybrid technology with the four-to-five-passenger RX 400h SUV. For someone whose mission is carpooling kids to sports and driving to work, this SUV does it in fuel-sipping style.

Well-executed hybrid drive vehicle. Superb fuel economy (for an SUV) around town. Ingenious electric-only drive for the rear wheels. Typical Lexus fit and finish.

Inadequate notification that car is started, in gear, in reverse. Navigation system voice input painfully slow. Odd hybrid sounds under acceleration. $2,650 Bluetooth option package. Nothing-special highway fuel economy.