Toyota's largest sedan stands out most for smoothness and quiet operation.The serenity is a function of many things, including the Avalon's underlying design, vibration-mitigating features and good build quality.Whatever the reasons, the Avalon is more tranquil than many sedans that cost a lot more.

The Avalon rides like a magic carpet, almost impervious to the worst roads you'll travel.But it also delivers good acceleration and mileage for such a roomy car.Its automatic transmission is quick shifting and decisive.It's pleasant to drive for just about any purpose, and it won't fail you if you happen to be in a hurry.

The interior is finished with quality materials and equipped with ergonomically functional controls.The front seats are roomy and comfortable, the back seat downright spacious.Empty-nesters will appreciate the Avalon for its flexibility, and families for its manageable base price, which includes a good stereo with CD changer and most of the features anyone really needs.

The Avalon also has the latest safety technology, starting with a full complement of front, side and head-protection airbags.It scores well in government and insurance-industry crash tests.And, in addition to the now-standard VSC skid-management electronics, it comes with traction control and an anti-lock brake system (ABS) with electronic brake-force distribution and brake assist.These features make sure that stopping power is distributed evenly, regardless of road surface, and that the brakes apply with full force in a panic stop.

It all makes the Avalon easy to like and even easier to enjoy.Think of it as a refuge from a hectic world.

For 2010, there are no significant changes.An all-new Avalon is being introduced for 2011.

The Avalon XL ($27,945) is well equipped, with a full complement of power accessories and features such as an eight-way power driver's seat, dual-zone climate control with cabin air filter and audio and climate controls on the steering wheel.The nine-speaker audio system includes a six-CD changer.Cloth upholstery and 16-inch alloy wheels are standard.

The Avalon XLS ($32,245) adds fog lamps, 17-inch wheels and leather seating.The XLS also comes standard with a power moonroof, heated outside mirrors with electrochromic auto-dimming on the driver's side, an auto-dimming rearview mirror with compass and Homelink universal transceiver, and an anti-theft system.

The Avalon Limited ($35,285) upgrades with a 360-watt JBL Synthesis audio system with 12 speakers and Blue Tooth connectivity, a power rear sunshade, Toyota's Smart Key proximity key system, HID headlamps, a wood-and-leather-trimmed shift knob and steering wheel, rain-sensing windshield wipers, and driver and passenger seat heaters and cooling fans.

Options include the power moonroof ($860) and anti-theft system ($220) for the base XL model.The XLS offers heated seats ($440), an eight-way power front passenger seat with heating ($740) and the JBL Synthesis sound system ($1,000).A navigation system is also available.Dynamic laser-guided cruise control ($600) is optional only on the Limited.

Safety features on all Avalons include active front seat headrests, which are intended to cradle the head more effectively in a rear impact and limit whiplash injuries.Vehicle Stability Control (VSC) is standard.All models also have anti-lock brakes (ABS) with electronic brake-force distribution (EBD) and Brake Assist.Occupant protection features include front-impact airbags, a driver's knee airbag, seat-mounted side-impact airbags for front passengers and side-curtain head-protection airbags for outboard passengers front and rear.

Overall, the Avalon is eight inches longer than Toyota's top-selling Camry sedan.By most exterior dimensions, the Avalon is roughly the same size as the Ford Taurus, Chevrolet Impala, and Chrysler 300.Compared to European luxury sedans, it's larger than the mid-size Mercedes E-Class, but smaller than the full-size S-Class sedan.

Lots of the Avalon's styling features have been optimized to reduce wind noise inside the car, including the shape of the windshield pillars and side mirrors and low placement of the wipers under the hood line.The Avalon Limited upgrades with unique, sound dampening glass in the windshield.

The Limited mirrors also include a couple model specific features, starting with LED turn signals in the glass that are visible to other drivers.We like the bright puddle lamps under those mirrors, because they flood the ground below the doors with light as you approach in darkness.

In front, the grille and bumper are trimmed with horizontal chrome bars, with fog lamps integrated into the lower bumper on XLS and Limited models.In side view, subtle character lines below the windows and above the door sills add a hint of sculpting to the Avalon's flanks.From the rear, the tall deck and big rear valance enhance the air of elegance and substance, while smoked tail light lenses add a hint of flair.

Materials are generally good quality.A very few trim pieces, such as silver-painted plastic parts and the housing around the steering column, demonstrate that the Avalon is not an extra-expensive luxury car.But the fit of the various parts and panels is impeccable and, overall, the Avalon's interior feels like quality.Even the extra-glossy, wood-grain trim Toyota designers seem so fond of looks pretty good inside the Avalon.

The front seats are big, fairly flat and comfortable.They don't have a lot of the side bolstering enthusiast drivers like for hard cornering, but the relative flatness makes then easy to slide into, and there's enough strategic bolstering to keep lower backs and backsides from becoming numb within a half hour or so.The seats will adjust for a wide range of drivers, and the controls make it easy to tailor your driving position; they are an excellent compromise between adequate adjustment and too many things to fiddle with.The Avalon Limited features a fan in the seat cushion and seatback that blows air through the perforated leather trim to improve comfort.

The steering wheel tilts and telescopes over a substantial range, and it's wrapped with leather on all but the base Avalon XL.The wheel spokes have buttons to adjust audio and climate settings, and those buttons are also a great compromise: Big and easy to find, but not confusing.Wipers and lights follow Toyota's familiar pattern, with the light switch on the left stalk and wipers on the right.Everything, from window and mirror switches to armrest heights, is positioned just as we like it.

The Avalon's dashboard layout is clean and simple, but not simplistic.Its so-called Optitron gauges are large, crisp and easy to see through the top half of the steering wheel.The large LCD informational display is located right in the center of the dash, above the switch stack.It offers a wide range of information, like inside temperature settings, outside temperature, time, date and fuel range, in large, easy-to-read script.

A touch-release cover below the LCD screen lifts to expose the audio controls.Those most frequently adjusted, including the tuner and volume control, are bigger than the knobs in most other cars.The six-CD changer is standard in all Avalons, and so is an audio jack to connect iPods or MP3 players.The upgrade JBL audio package adds Bluetooth capability and 360 watts of output.It sounds fantastic, though we could certainly live with the standard stereo.

The primary temperature, air flow and fan adjustment knobs are huge, located on either side of the stereo and prominently back-lit in pastel turquoise that reminds us of Miami Beach.They operate with a firm, steady action, and they're nearly impossible to miss when the driver reaches a hand from the steering wheel.

The sunroof button and overhead light switch are located above the rearview mirror, with a drop-down sunglasses holder.One omission is the Avalon's lack of individual reading lights for front-seat passengers, and the omission is more glaring because the interior is generally so nice.Buttons for the seat warmers are dials offering a range of heat intensity, located on the center console next to the gear selector.

The center console itself is simple but effective, with three touch-release doors.One door exposes the cupholders, and the others reveal storage compartments.The larger compartment has two power points and the audio jack.There's also a felt-lined change bin.

The Avalon's door pockets have no lining material, and the hard plastic allows items such as sunglasses to slide (and potentially scratch) easily.Still, those pockets are wide and deep, and we love how they swing open like a folder to allow an easy reach inside.The glove box will swallow a whole lot of gloves, along with a clutch or handbag.

The Limited model comes with a rear glass sunshade, operated by the driver.The sunshade lowers automatically if it's up when the driver engages Reverse, then lifts it again when the driver selects Drive.

The Avalon's rear seatbacks recline over a limited range (still a rare feature), and the feeling of roominess carries through in back.Leg room for rear passengers surpasses that in many taxis: With the driver's seat adjusted for a 5-foot, 9-inch driver, a 5-foot, 9-inch passenger had enough room to stretch legs fully, with feet pointed under the front seat.The rear bench's width is impressive, too.Three-across seating is no problem here, and accommodations are improved by the flat rear floor.Headroom is somewhat short, but still adequate.That 5-foot, 9-inch passenger was brushing his close-cropped hair on the headliner with the rear seat back in its most upright position.Adjusting the seatback to maximum recline adds an inch or two of headroom.

Individual reading lights are provided for rear passengers, with adjustable air vents on the rear of the center console.The rear door pockets don't fold open like those in front, but there are stretchy map pockets on the front seatbacks.The rear armrest drops a little too low for our taste, and the shallow cupholders built into it are more like cup stabilization points.They are cupholders only if there is a hand helping hold the cup.

At 14.4 cubic feet, trunk capacity is less than in many similarly-sized competitors.There's still decent room for luggage or a serious shopping binge, but the Avalon trunk is further hampered by its basic shape.The trunk is long but relatively narrow, with much of the available space stretching forward toward the rear seatback, under the rear glass and shelf.The trunk lid raises itself once you open it, something many trunk lids don't do.Yet the trunk opening is smaller than that on other cars in the Avalon's class and small relative to the trunk's volume, so large items that might fit in the trunk may not fit through the opening.

A locking pass-through allows longer items such as skis to slide into the cabin between the outboard rear passengers, though the Avalon does not offer the folding rear seatbacks available on some competitors.A standard, removable cargo net hangs within easy reach across the trunk opening to keep items such as plastic grocery bags from dumping or sliding around during transport.

The foundation for the Avalon's smoothness is its powertrain.On paper, its 3.5-liter V6 engine might seem a bit small for a relatively large car.In fact, the Avalon is surprisingly peppy.The dual overhead-cam V6 generates a substantial 268 horsepower and 248 pound-feet of torque, and it moves the Avalon with authority.Moreover, thanks to variable valve timing and a dual-stage variable intake manifold, the power isn't the least bit peaky.It flows smoothly and evenly from idle to the engine's 6200-rpm limit, whether you're accelerating casually from a stop sign or flooring the gas pedal to merge onto a crowded freeway.

The V6 has enough torque to create a bit of torque steer when you floor it from a slow speed.Torque steer usually manifests itself as a slight tug on the steering wheel under hard acceleration.In the Avalon, it's nothing that will disturb the typical driver, but it's enough to let that driver know that there's a powerful piece under the hood.The Avalon will easily accelerate from 0 to 60 mph in less than eight seconds and, while that's no longer sports car performance, it's anything but lethargic, especially in a large car that carries five people and their luggage with lots of room to breathe inside.

Fuel economy is among the best in its class, with an EPA-estimated 19/28 City/Highway mpg.Those numbers are more than respectable in a car this big and roomy.This is thanks in part to the Avalon's six-speed automatic transmission.

The six-speed automatic uses the latest electronic controls and a unique mounting system designed to minimize the transfer of shift-shock into the Avalon's cabin.It does a great job of tapping the horsepower available, and it almost always knows the best time to shift, whether it's up or down.The shifts are reasonably quick, but they're also exceptionally smooth, even at full throttle.Light-throttle upshifts are barely noticeable.

The top gear is a tall overdrive, so the Avalon cruises in relaxed fashion on the freeway, with the engine spinning quietly at relatively low speed.We tried the transmission's manual shift feature on a swoopy two-lane road, tapping the sequential shift lever between second and third and keeping the engine spinning near its redline.We discovered in the process that the Avalon can be something like a sport sedan, because the V6 is happy to run at high rpm.

Still, this sedan is built primarily for comfort, and that's obvious in the suspension settings.The ride is silky smooth in nearly all circumstances, and rarely does a road shock ruffle the occupants.The softly tuned suspension means the Avalon might lean noticeably in faster turns.Yet the body movement is well controlled, and the Avalon doesn't feel floating or disconnected.Its steering is on the light side, with a lot of power assist, but it responds directly to movement of the wheel.We might call the Avalon cushy but good.It holds its line nicely when driven reasonably quickly through a series of curves, whether the road surface is smooth or bumpy.

The Avalon's brakes are strong and they stop the car with authority.The brake pedal feels a little softer than we'd like, but it's linear in operation and it makes it easy for a driver to smoothly apply stopping force.Its effective anti-lock brake system keeps Avalon on an even keel during panic stops and allows the driver to maintain steering control.

In short, the Avalon is up to whatever the typical driver might encounter or dish out.Yet its trademark might be the peaceful stillness inside.At a stoplight in the city center, the whirring hubbub outside the Avalon sounds like a muted purr to its driver and passengers.At 75 mph on the expressway, about the only sound you'll hear is a soft crack from the tires as they slap over pavement joints, and 15 percent volume with some soft music will take care of that.The Avalon is exceptionally smooth, too, especially for its price.At freeway speeds, you'll feel less vibration through the steering column, seat bottoms or floorboards than you would in some luxury cars that cost $20,000 more.

There's not much we don't like about the Avalon.Some driving enthusiasts would say it's too vanilla, but then it's doubtful that hard-core driving enthusiasts are interested in this car, anyway.We'd say it's competent, pleasant to drive in all circumstances, and never aggravating.That last point can be huge on hectic days.

NewCarTestDrive.com correspondent J.P.Vettraino reported from Detroit, with John Stewart reporting from Carmel-by-the-Sea, California.