Introduced last year, the Buick Lucerne replaced both the LeSabre family sedan and the Park Avenue luxury sedan in Buick's full-size lineup. For 2007, the brand's biggest car is essentially unchanged save for some new colors and the availability of a heated steering wheel.

Built at the same General Motors factory that makes the Cadillac DTS, the Lucerne shares the Caddy's 115.6-inch wheelbase (though overall length is 4 inches shorter). The top trim level, the CXS, comes with a 275-horsepower Northstar V8. The other two trims, base CX and leather-lined CXL, have the proven 3.8-liter, 197-horse V6 as standard, with the Northstar available as an option on the CXL. The Lucerne CXS also features GM's Magnetic Ride Control (MRC) suspension. Able to adjust shocks' damping within milliseconds, MRC allows a traditionally Buick-plush ride for normal driving while sportier driving will firm things up to minimize body sway in the corners.

The Lucerne's styling provides a subtle link to Buicks of decades past via the portholes seen in the front fenders. V6 models have three portholes, while V8s have four. And as the company's flagship, the Lucerne is fitted with Buick's "Quiet Tuning" technology that reduces road, engine and wind noise, and indeed it is one of the most serene cars in its class.

Although there are plenty of standard features on the Buick, now-common luxury items like full one-touch windows, a telescoping steering wheel and power-adjustable pedals aren't available. Also missing from the available features are xenon HID headlights and Bluetooth wireless capability.

While the 2007 Buick Lucerne is generally a well-rounded large sedan, many of its peers, such as the Chrysler 300, Hyundai Azera and Toyota Avalon beat it in the areas of features, refinement and performance. Depending on how you equip it, the Lucerne can be less expensive than either the 300C or the Avalon, but it's a tough sell over the Azera, which is not only cheaper but more upscale in feel and stronger in performance.

The 2007 Buick Lucerne is a large sedan available in three trim levels: CX, CXL and CXS. The CX comes with 16-inch alloy wheels, keyless entry, full power accessories, a driver seat, OnStar telematics, a CD player and steering-wheel-mounted audio controls. The CXL adds leather upholstery, 17-inch alloy wheels, heated outside mirrors, rain-sensing wipers, a power passenger seat, auto-dimming rearview mirror, dual-zone automatic climate control and an MP3-capable stereo with an auxiliary audio jack. The CXL trim also allows access to additional optional equipment like heated and cooled seats and heated windshield washer fluid. The top-line CXS comes with driver-seat memory, heated front seats, a 280-watt Harman Kardon audio system, satellite radio, 18-inch alloy wheels, a heated steering wheel and Buick's MRC suspension. Optional on all Lucernes are a CD changer, a moonroof, remote vehicle-starting and rear park assist. Available on the upper trims are heated and cooled seats and a navigation system.

The CX and CXL are powered by a 3.8-liter V6 that provides 197 horsepower and 227 pound-feet of torque. Available on the CXL and standard on the CXS is a 4.6-liter V8 rated at 275 hp and 290 lb-ft of torque. Both engines send their power to the front wheels through a four-speed automatic transmission. Our test of a V8-equipped CXL yielded a 0-to-60-mph time of 7.7 seconds, respectable yet not as quick as a couple of speedy V6 competitors such as the Avalon and Azera.

Standard across the line are antilock disc brakes, traction control, a tire-pressure monitor, front side-impact airbags and full-length, head-protecting side curtain airbags. Stability control and brake assist are standard on the CXS, optional for V8-equipped CXL models and not available on V6 Lucernes. In NHTSA crash tests, the 2007 Buick Lucerne earned a five-star rating (out of a possible five) for its protection of the driver and front passenger in frontal impacts. A four-star rating was given for side-impact protection of front and rear occupants. In IIHS tests, the Lucerne scored a "Good" rating (the highest of four) in frontal-offset testing and an "Acceptable" (second highest) in that agency's side-impact test.

A plush, serene ride is the top priority for the Buick Lucerne. Handling is mediocre on the softly tuned Lucerne CX and CXL styles, which exhibit considerable body roll during cornering. The high-line CXS model is another animal, as it's fairly nimble through turns thanks to its MRC suspension and larger performance tires. The steering feels wobbly on-center in CX and CXL V6 models, so upgrading to the variable-assist Magnasteer setup available on the CXL V8 and CXS is advised. The brakes are somewhat disappointing. Pedal feel is fine in everyday traffic, but panic stop distances are the longest of any full-size sedan in this price range.

The Lucerne's cabin is handsome and cleanly styled, and boasts simple controls. The leather upholstery is soft, and the grain patterns of the materials used on the dash and doors are well-matched. Unfortunately, there are still a few low-grade plastic pieces thrown into the mix and build quality is inconsistent. Standard seating is typical, with bucket seats and a console, but a split bench seat can be ordered for the CX and CXL, thus increasing passenger capacity to six. Cushioning and legroom are abundant, whether you're seated in the front or back. The trunk holds up to 17 cubic feet of cargo and features a ski pass-through.