The optional V8, however, provides much better acceleration. Tweaked for 2005, the Vortec 5300 V8 now rates 300 horsepower and 330 pound-feet of torque (torque being the force that you need to pull around a trailer). We found the V8 to be extremely quiet in the Rainier.

Regardless of our quibbles about Rainier's interior appointments, there's no debate about its quiet ride. This very likely is the quietest body-on-frame SUV we've ever driven. Buick used the Lexus LX 470 as the target for Rainier, but we think Rainier itself sets a new benchmark when it comes to a quiet cabin. Double-pane, laminated glass was used for the windshield and front doors; acoustical foam sound-deadening material was used liberally to fill the doors, roof pillars and other empty spaces in the body.

Rainier rides on an independent double A-arm front suspension, and a live rear axle with electronically controlled air springs providing automatic leveling. Bilstein shocks dampen the bumps all around. This is, essentially, the optional suspension for the GMC Envoy. Combined with quiet Michelin tires and all that extra sound dampening material, Rainier's suspension provides a smooth, comfortable and quiet ride. But it isn't soft or sloppy. We found the Rainier sure-footed even when being hustled along narrow, winding country byways.

Rainier's rack-and-pinion steering is nicely weighted. The big disc brakes responded immediately to pressure on the pedal and slowed our Rainier in a nicely composed and orderly fashion.

All-wheel drive makes the Rainier a good vehicle for driving on snow and ice. Rainier's available on-demand all-wheel-drive system is lightweight, quiet and efficient. If one or both front wheels lose grip, the system goes into action progressively. The driver need do nothing; there are no buttons to press or levers to throw. The system works all the time, poised to help drivers make use of the traction available by transferring torque from rear to front tires as needed.

The optional navigation system ($1,995) features an amazingly clear screen that seems almost immune to glare from sunlight, which often renders such screens unreadable in other vehicles. We found last year's system awkward to operate, but Buick claims to have fixed this with new touch-screen controls for 2005.

GM's OnStar safety and security system is standard on all 2005 Rainier models and includes a one-year subscription to the Safe & Sound plan. It's a great safety feature. On the 2005 Rainier, OnStar service includes the new General Motors Advanced Automatic Crash Notification (AACN) system, making crash data available to 911 centers to potentially dispatch the appropriate life-saving personnel and equipment to crash scenes faster. New-generation hardware for 2005 means upgraded hands-free voice recognition capabilities including more intuitive continuous digit dialing and improved voice recognition accuracy. OnStar is the leading provider of in-vehicle safety, security and information services in the United States and Canada. Using the GPS satellite network and wireless technology, OnStar provides core safety services and OnStar Personal Calling that allows drivers to make and receive hands-free, voice-activated phone calls using a powerful three-watt digital/analog system and external antenna for greater reception. Press a button and an OnStar operator's voice comes over the speakers, ready to give you directions to the nearest five-star restaurant or provide other assistance.