The optional V8, however, delivers much better acceleration performance. The Vortec 5300 V8 delivers 290 horsepower and 325 pounds-feet of torque, that force that you need to pull around a trailer. We found the V8 to be extremely quiet in the Rainier.

Buick worked hard to ensure a smooth ride quality. The Rainier is equipped with a double-A arm independent front suspension, Bilstein shocks, and an electronically controlled rear air suspension with automatic leveling technology. Basically, this is the optional suspension for the GMC and Chevy models. Combined with the quiet Michelin tires and extra sound dampening equipment, the Rainier provides a smooth, comfortable and quiet ride. But it isn't a cushy ride. We found that the Rainier was sure-footed even when being hustled along narrow, winding hill country byways.

The rack-and-pinion steering was nicely weighted. The big disc brakes responded immediately to inputs to the pedal and slowed the Rainier in a nicely composed and orderly fashion.