In naming the Lucerne, the overhauled fullsize sedan that replaces the Buick LeSabre and Park Avenue, the brand's honchos may have been trying to impress the world with their knowledge of Swiss geography.

So, Buick's leaders can read maps. But do they know where the brand is heading?

Buick's current lineup is almost all-new but has little heritage on which to draw, and it's with these little-known products that the brand is attempting to resuscitate its fortunes amid years of sliding sales. During the last two years, Buick introduced its first minivan and SUV and replaced the longstanding Regal and Century with the LaCrosse sedan.

But the '06 Lucerne, which is based on the same front-wheel-drive “G” platform as the Cadillac DTS, represents perhaps the most crucial turn in Buick's drive to revive. Replacing the flagship LeSabre, Buick's best-known nameplate and sales leader, with deliveries of 114,157 units in 2004, is a tricky road to navigate.

Sales of Buick's other six models totaled 195,482 units last year. If the Lucerne veers off course, Buick's destination might be the automotive graveyard.

After spending several hours driving the Lucerne, we doubt Buick needs to scope out a burial plot next to Oldsmobile.

This large 4-door isn't the image-altering product Buick desperately needs, but it points the General Motors Corp. near-luxury division in the right direction.

The ambiguous styling of the LeSabre is gone. The Lucerne features more prominent hood lines and a bigger grille. Chrome-ring portholes adorn both front quarter panels: three for cars using the base 6-cyl. engine and four for V-8-powered Lucernes. Call them the Lucerne's jewelry — a nice touch of attitude.

The LeSabre's rounded stern is exchanged for the Lucerne's flat and crisp rear sheet metal, featuring smaller taillamps and a hint of a spoiler on the decklid.

Disappointingly, the Lucerne's exterior does not hide its stretched dimensions. With an overall length of 203.2 ins. (516 cm), the Lucerne is more than 3 ins. (7.6 cm) longer than the LeSabre.

The Lucerne's size results in more interior space, but not as much as one might expect. Only in rear legroom is there a noticeable increase, a hard-to-ignore 5.5-in. (14 cm) bump over the Lexus ES 330, the Lucerne's primary competitor.

Interior styling is simple. But the flush center stack and chrome-ringed gauges help make the Lucerne's cabin competitive, unlike the outdated LeSabre.

Under the hood of the base CX and midlevel CXL resides GM's 3.8L OHV V-6, churning out 197 hp and mated to a 4-speed automatic transmission. Somehow, Buick never realized overhead-cam V-6s making horsepower in the mid 200s and 5-speed automatics now are the segment's norm. This V-6 lacks refinement and is just plain uncouth for a lower-luxury sedan.

Meanwhile, the Lucerne marks the return of V-8 power for Buick passenger cars, with the 275-hp 4.6L Northstar all-aluminum powerplant. It is optional with the CXL and standard with the uplevel CXS.

Midrange performance is hampered somewhat by the engine's pairing with the 4-speed transmission. Otherwise, the Northstar is delightful in its new Buick home. Acceleration from a dead stop is invigorating, and the engine sings beautifully at full throttle.

The front suspension setups are numerous, depending on trim levels, including independent MacPherson strut coil-over-spring and twin-tube dampers. The rear suspension is multi-link independent with coil springs and a semi trailing arm with twin-tube airlift control dampers.

The magnetic ride control system is an impressive addition to the upscale Lucerne CXS. There is minimal body roll around corners, and there's plenty of damping reserve in dips. It is a fantastic ride. However, the base CX, with the standard suspension, drifts like blowing snow.

The Lucerne began arriving in dealerships in November. Pricing begins at $26,990 and tops out at $35,990.