- Hushed ride

- Powerful V8 option

- Easy ingress and egress

- Respectable off-road ability

- Inconsistent build and materials quality

- Sloppy handling

- Missing some key safety features

- Lacks storage space

As expected, the 2007 Rainier's forte is a plush, quiet ride. Power is ample with the standard inline six, and more than enough with the optional V8. Indeed, consumers who go for a spin around the dealer's block may be initially impressed, and the Rainier's truck-based chassis also proves capable off-road. But in the real world of workday commutes, day-care carpools and unpredictable drivers, the Buick Rainier's lack of confident handling at higher speeds hurts it when compared to segment leaders such as the Toyota 4Runner, Mercury Mountaineer and Volkswagen Touareg. Any of those will provide an equally comfortable ride along with a more sure-footed feel during everyday driving and especially during quick transitions, such as when performing an evasive maneuver.

The Buick Rainier comes as a five passenger, four-door SUV in one CXL trim level. Standard features include 17-inch alloy wheels, leather upholstery, simulated wood accents, power front seats, memory positions for the seats and mirrors, dual-zone automatic climate control, a CD player and OnStar telematics. Among the options are a sunroof, power adjustable pedals, heated seats, satellite radio, a six-disc CD changer, a navigation system and a rear-seat DVD entertainment system.

Stability control, antilock disc brakes and a one-year subscription to OnStar are standard. Optional are full-length head curtain airbags. Although seat-mounted side airbags are not available, a side curtain airbag-equipped 2007 Buick Rainier received five stars (the highest rating possible) in NHTSA's side-impact testing for front- and rear-passenger protection. In NHTSA frontal-impact tests, the Rainier garnered a three-star rating for the driver and four stars for the front passenger. However, in IIHS frontal offset testing, the Buick managed just a "Marginal" rating, the second lowest out of four.

Sadly, the Rainier's cabin furnishings are heavily derivative of GM's lower-line SUVs and fail to provide the authentic luxury ambience required in an upscale vehicle. The leather upholstery on the seating surfaces looks and feels luxurious, but the accompanying vinyl trim used elsewhere on the seats is of low quality. Handsome gauges help, but those are offset by iffy ergonomics that include GM's convoluted three-on-one signal/wiper/cruise stalk and a tiny black nub that's used for power mirror adjustment. The cabin is noticeably quieter when compared to nearly any other SUV in this price range, but seat comfort is only average. With the rear seat folded down, there are 80 cubic feet of cargo space.

The inline six doesn't feel particularly strong at lower rpm, though it comes alive once in the midrange. Equipped with the "5300" V8, the Buick Rainier has more than enough power to get around quickly. Highway passing maneuvers are effortless as well, even on steep uphill grades. Handling dynamics are not equal to the Rainier's strong straight-line performance, however. Although truck-based SUVs are still not expected to have the reflexes of cars (or even car-based SUVs), the Buick SUV and its GM stablemates fall well behind peers like the 4Runner, Durango and Mountaineer. When asked to make rapid directional changes during slalom testing, the rear end tends to feel skittish. Standard stability control will keep it on course in most situations, but still, this kind of behavior and seat-of-the-pants feeling does not instill confidence when faced with real-life emergency maneuvers. Likewise, the steering feels sloppy on center and generally disconnected because of slow responses and a lack of road feel.

That much was expected, as General Motors said during the Detroit unveiling that a production version of the Enclave would be the replacement for its Rendezvous crossover model for 2008.

But it comes as a surprise that although the Enclave will appear as an early 2008 model, initially sold alongside the Rendezvous and Buick Rainier, both of the latter two sport utilities will be discontinued after the 2007 model year, according to a report this week in the industry weekly Automotive News.

The magazine quoted Buick marketing director Brian Bowden about the plans for the Enclave, Rendezvous and Rainier, but through a spokesman, Bowden last week denied saying that, and GM would say only that an announcement about the plans for Buick SUVs would be coming soon.

"Brian did not make those comments," GM spokesman Craig Eppling said.

"The official word is that these products (Rainier and Rendezvous) are in the portfolio for the time being, and no official announcement has been made to the dealers or the public about the Enclave, Rainier or Rendezvous."

But he added that an announcement probably will be made soon, and it has been clear from the start that the Enclave would be the replacement for the Rendezvous, Buick's first truck product in 80 years when it was introduced for 2001.

The Rendezvous was one of the first of the new wave of crossover utility vehicles to hit the market. The crossovers, which are car-based as opposed to the truck-chassis roots of the traditional SUV, have this year overtaken the truck-based SUVs in overall sales.

The Rainier, introduced two years ago, is a true truck-style SUV, cloned from the midsize Chevrolet TrailBlazer/GMC Envoy sport utilities that were introduced for 2002.

The biggest difference for consumers is that the Rendezvous comes with a third row of seating, while the Rainier does not.

There are extended-length models of the TrailBlazer and Envoy that have a third seat, but GM chose to give Buick's Ranier only the shorter five-passenger model because the Rendezvous was already in the lineup offering a seven-passenger SUV.

The Rainier has the traditional body-on-steel-frame arrangement of a truck, but the Rendezvous and the new Enclave have carlike unibody construction, which is lighter, rides more smoothly, and generally produce at least slightly better fuel economy.

Buick got the Rainier the year after GM discontinued production of the similar Oldsmobile Bravada, the last new vehicle in the Olds lineup before the entire brand was dropped. The Rainier was designed to take up the slack in GM midsize SUV production caused by the Bravada's demise, and continue to give consumers an upscale version of the TrailBlazer/Envoy like the Bravada.

Truck-based SUV sales are on the decline as more crossovers come to market, and Buick's decision to drop the Rainier, if it's true, probably makes sense.

Focusing on the Enclave would give it a better shot at becoming a best-seller among the overall Buick lineup, which also includes another truck product, the Terraza sport van, introduced last year, and two sedans, the upscale Lucerne, which is new for 2006, and the midsize LaCrosse, which came out last year.

GM will build the Enclave at its new Delta Township plant near Lansing, Mich., Automotive News said. The design is based on GM's new Lambda crossover utility vehicle platform, which also will be the basis for two other new models -- the 2007 Saturn Outlook and the 2008 GMC Arcadia.

The magazine also quoted Bowden as saying that slack in the production schedule at the Moraine, Ohio, plant that builds the Rainier will be taken up by the Envoy, and that production of the Rendezvous will cease at the end of this year at the Ramos Arizpe, Mexico, plant.

As gasoline prices remain high and consumers continue to lose interest in traditional truck-based SUVs, the automakers are responding by rolling out yet more of the crossovers. Besides the Enclave, several others have been introduced at this year's major auto shows.

More than 2 million crossovers were sold during 2005, and their sales are on pace to exceed those of traditional SUVs for all of this year.

These smoother-riding, car-based models, which some automakers are now calling "CUVs" (for crossover utility vehicle), include such pioneer nameplates as the Toyota Highlander, Lexus RX 330, Ford Escape and Nissan Murano. They represent the fastest-growing segment in the sport utility genre.

Women, who often use sport utilities to haul kids to school and weekend activities, have so far constituted the largest market for crossovers, even before rising fuel prices began to put a crimp in sales of traditional SUVs.

Among the models introduced so far this year are the 2007 Ford Edge, a midsize crossover slightly smaller than the current Freestyle; the compact Mazda CX-7, a sporty five-seater with a turbocharged engine; the midsize Lincoln MKX, which replaces the truck-based Aviator; and a radically restyled Acura MDX, which made its debut at the New York auto show.

Hyundai also has a redesigned midsize Santa Fe on the way, a crossover that grows enough to allow for a third row of seating.

Styling is one of the ways that some crossovers have differentiated themselves from traditional SUVs. Moving away from the boxy looks of the truck-style SUVs, some of the crossovers are quite beautiful. Among the most unusual models are the Nissan Murano and Infiniti FX, which look more like futuristic station wagons than boxy SUVs.

The Edge and MKX are built on the same architecture and are very similar, even down to using the same engine and transmission. The Edge, though, will have a mass-market price, while the MKX, which Lincoln says should be pronounced "Mark X," will be essentially a luxury version of the Edge with a correspondingly higher price tag. Both will be built on an assembly line at Ford's Oakville plant in Ontario, Canada.