The Impala has been changing, morphing, and maturing with the vagaries of the market since 1958 when the first one showed up as a coupe and convertible.

Now, the Chevrolet Impala has been substantially upgraded for 2006. The 2006 Impala features new and very attractive exterior styling, a new interior, and a choice of three new engines.

The new Impala is a comfortable and convenient car, roomy, easy to get in, with big grab-style door handles. It's a practical sedan with Innovative flip-and-fold back seats and folding rear seatbacks. And it comes well-equipped with safety features, including side-curtain airbags. The Impala LT best exemplifies the model line, especially when ordered with the larger, 3.9-liter engine, which delivers responsive performance. The LTZ upgrades with leather, a very nice XM Satellite Radio setup and other convenience features.

An inexpensive pricing structure with loads of rebates on it puts the new Impala on the shopping list for family sedans. Impala competes with the Ford Five Hundred, Chrysler 300, Dodge Charger, Honda Accord, Toyota Camry, and Nissan Altima.

The SS stuffs a small-block V8 into this package. It sounds great and delivers strong acceleration performance, but it's a lot of power for this front-wheel-drive sedan.

It has been a long, long time since a Chevrolet sedan rang our design chimes, a long chain of cars with geeky, strange design licks all over, but this new Impala is a really clean, neat, pleasing design that's not so homogenized as to be boring.

The new Impala features bigger, more thoroughly integrated headlamps and taillamps. Underneath, it gets a stiff new body and chassis structure, retuned suspensions with a 10-mm wider track, and new 16-, 17- and 18-inch wheels and tires.

The LS, LT and LTZ share one front end design, while the SS has a completely different nose architecture.

The new Impala has a lot going for it inside as well, with a completely new, cleaned-up interior, reshaped and reupholstered seats, and flip/fold rear seats.

We felt pretty comfortable overall inside the Impala. The seats have firmer cushions and increased lumbar support than previous models. We didn't find the SS seats particularly comfortable or supportive, with too much lumbar support and not enough side bolstering to retain the upper body in corners. Optional leather-covered seating has a new style of seams around the perimeter and French seams on the center sections.

The Impala also has a new twin-brow instrument panel design that wraps around into the door panels. LS, LT and LTZ models have a wood trim, with brushed silver trim optional. The Impala SS comes standard with metallic trim panels, with wood trim as an option. We found the panel pleasing to the eye, colorful, entertaining and easy to use, with a nice all-of-a-piece unity and style to it. We found the interior materials at least one grade better than the usual Chevrolet stuff.

The optional dual-zone climate control system can have up to a 12-degree temperature difference side-to-side. It's a snap to use, with large, round control knobs and good markings. The optional remote engine start system comes with a 200-foot operating range and automatic climate pre-conditioning to warm or cool the interior. The dashboard has an expanded driver information center, now with more than 50 different alerts, depending on the vehicle's equipment. The glovebox is 20 percent larger than previous models, which means you can actually put stuff in it larger than a ballpoint pen.

A new family of audio systems features radios compatible with the Generation 6 OnStar system. The base audio system includes AM/FM/CD and six speakers. An optional MP3/CD-radio is configured for XM Satellite Radio, with a two-line, 32-character display and the capability to select freely between AM, FM and XM. We really liked this system because we could set up all of our favorite stations in one row, for example, allowing us to quickly switch between AM news, XM news, and FM music stations. Setting these presets is as easy as holding the button down. A big round knob in the center allows quick volume adjustments. Presets for the equalizer let you quickly switch settings from rock to country & western to talk radio. The optional ICDX radio adds an in-dash six-CD changer. Impala also offers a premium Bose audio system. All radios include a standard auxiliary input jack for external devices such as an iPod or remote cassette player.

The rear seat is roomy and comfortable for two adults or three kids, but not three adults. The rear seat cushions flip forward to create a covered storage area under the seat (with cushions down) and grocery bag hooks when the cushions are flipped. The seatback also folds down flat to create a large pass-through port to the trunk.

Trunk space, at 18.5 cubic feet, is more than competitive in the segment, and it has a huge opening for easy loading.

The new Chevrolet Impala comes with a new generation of V6 engines. We found them to be smooth and quiet if not bristling with power. Variable valve timing is a first for the Impala's cam-in-block V6 engines. The system changes the orientation of the camshaft, automatically adjusting the timing of the intake and exhaust valves for better performance, economy, and emissions. Thus, a system that started out on very expensive imported cars has now reached down to the lowly Chevy V6 engines and made them better.

The 3.5-liter V6 that comes on LT and LS models generates 211 horsepower and 214 pound-feet of torque. The 3.9-liter V6 that comes on LS and LTZ models produces 242 horsepower and 242 pound-feet of torque. We're expecting both engines to earn fuel economy ratings of about 19/29 mpg city/highway.

With 303 horsepower, the Impala SS has more power and torque than any other entry in the class, but the chassis that comes with the V8 needs taming. The traction control system simply gets behind in its orders whenever you slam the throttle open at a stop in first gear, and lets the left front tire spin wildly for a few seconds until it finally catches up. While we appreciated the extra power and torque available in a kickdown or passing situation, and we loved the brawny, muscular sound of this engine at full throttle, it's a challenge to launch cleanly and quickly at the same time. Besides wheelspin, there's a lot of torque steering. Slam down the throttle and you'll feel a tug on the steering wheel as the powerful 5.3-liter V8 tries to put over 323 pound-feet of torque through the front wheels. The V8 features GM's Displacement on Demand system, which shifts between eight-cylinder and four-cylinder operation, depending on speed and load. This system helps provide up to 8 percent better fuel economy in light-load driving conditions. The V8 is EPA-rated at 18 city and 28 highway with the four-speed automatic.

The Impala offers three levels of suspension tuning, FE1 3.5, FE1 3.9, and FE3 for the V8, each designed to match the performance of the engines. However, there is a lot of pitch, dive, and body roll in this chassis, and a lot of uncertain driving moments with the added power of the SS. Steering is over-assisted, fairly numb and uncommunicative.

The Impala's front suspension is a MacPherson strut coil-over-spring independent design, with gas-charged struts and a stabilizer bar with new, taller jounce bumpers. The rear suspension uses a trailing arm, tri-link setup with gas-charged struts and coil springs. A rear stabilizer bar is standard on all models. On the SS, it seems, they needed a little more time to get it right, time they apparently didn't have.

We found the ventilated front disc/solid rear disc anti-lock brakes very much to our liking, powerful, direct, and linear, with a nice, progressive ratio of pedal travel to stopping progression. The Impala's four-wheel-disc brake system represents an improvement over previous versions, with new front brakes, improved rear brakes, and a new brake booster, designed for quieter operation, longer pad life, and more resistance to brake pulsation. The new ABS includes Electronic Brake-force Distribution.

The 2006 Chevrolet Impala spans a broad model range and includes the base LS, the middle-range LT, the loaded LTZ, and the high-performance SS.

The LS ($21,330) comes with the 211-horsepower, 3.5-liter V6, and a four-speed automatic transmission. It comes with the bare essentials, such as air conditioning, power windows and locks, AM/FM/CD, cruise control, cloth upholstery, a bench seat, and 16-inch steel wheels. Anti-lock brakes are optional ($600).

The LT is available with the 3.5-liter V6 ($21,860) or a new 3.9-liter V6 ($24,760), which includes 17-inch alloy wheels. The LT comes standard with dual-zone air conditioning, bucket seats, ABS, traction control, dual exhaust, fog lights, remote starter, power outlets, and a rear spoiler.

The LTZ ($26,870) is powered by the 3.9-liter V6 and is upgraded with leather upholstery, heated seats, upgraded audio with MP3, XM Satellite Radio, a leather-wrapped steering wheel with audio and cruise controls, and 17-inch wheels.

The SS ($27,130) boasts a 303-horsepower, 5.3-liter V8 with Displacement on Demand and a four-speed automatic. The SS comes with 18-inch wheels and tires and a performance suspension.

Safety features that come standard include dual front smart air bags, and side-curtain roof-mounted air bags. All but the base LS model come standard with anti-lock brakes (ABS) and traction control.