ST. LOUIS – Time to bury those old jokes. You know the ones.

What does B-U-I-C-K stand for? Big-Ugly-Imitation-Chrome-King.

For the better part of two decades, the venerable brand has been stigmatized as a retiree’s ride. But since the Lacrosse and Lucerne sedans launched in 2004 and 2005, respectively, Buick has been engaged in a race to become relevant.

The carefully executed cars have helped raise the bar. But the ’08 Enclave cross/utility vehicle completes Buick’s journey from running gag to checkered flag.

Elegant without pretentiousness, it offers superior refinement without diluting the driving experience.

Benefiting from a trademarked process GM calls “QuietTuning,” the Enclave sets a new standard for tranquility. QuietTuning starts with aerodynamics, immediately evident in the dramatic roofline that affords a drag coefficient of 0.358, and continues with inspired material choices such as the acoustic laminated glass found in Enclave’s windshield and the composite cam covers.

Factor in the acoustic foam used to seal the body structure, and a computer-modeled Michelin tire tread design exclusive to Enclave, and the result is a level of quiet once considered the sole domain of Lexus. By comparison, Toyota luxury marque’s RX 350 is categorically clunky.

In addition to sales, which are strong through August, another measure of Enclave’s refinement is the comparison with its sister vehicles, the Saturn Outlook and GMC Acadia. Despite sharing the same underpinnings, the Enclave bests the other two seemingly by an order of magnitude.

Wind noise is non-existent and road noise, dampened also by the use of laminated sheet metal in the fresh-air plenum area, is reduced to a faint hum. This makes conversation easy throughout the cavernous interior that can hold up to 18.9 cu.-ft. (.54 cu.-m) of cargo when all three rows of seats are deployed – 4.3 cu- ft. (0.12 cu.-m) more than its closest competitor, the Acura MDX.

The downside, of course, is that front-row occupants no longer have a convenient excuse when ignoring third-row occupants.

The genuine downside is, despite Enclave’s capacity for up to eight occupants, it has just six head restraints. Eschewing the safety argument in favor of equipping every seating position with a head restraint, Buick takes the low road and cites consumer complaints about compromised visibility.

(What would consumers say if they were asked to choose between a completely unobstructed view and whiplash? Just wondering.)

However, the attributes that will put the most distance between the Enclave and the Buick of old is performance. A 275 hp 3.6L DOHC V-6 mill offers throttle response that mitigates the front-wheel-drive version’s lofty 4,780-lb. (2,168-kg) curb weight, which balloons to 4,985 lbs. (2,261 kg) with addition of all-wheel drive.

Independent front and rear suspensions keep the vehicle planted on all surfaces, while a direct-acting front stabilizing bar enhances the variable-effort, hydraulic rack-and-pinion steering. The outcome is a nimbleness that belies the vehicle’s considerable 201-in. (518-cm) length and enables a turning radius of 40.4 ft. (12.3 m).

The Enclave’s greatest triumph, however, is its styling. Its exterior is sleek where its sister CUVs are boxy, while its interior features fluid lines in keeping with the level of sophistication expected of the triple-shield brand.

Nobody’s laughing at Buick now.

emayne@wardsauto.com