Apart from the availability of a heated steering wheel, an upgraded version of OnStar and the shuffling of a few color schemes, nothing changes for the 2007 Buick Lucerne. GM has also extended the powertrain warranty on all of its models to five years/100,000 miles. Performance & mpg 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. Safety 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. Driving 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. Interior 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.