2006 buick rainier review this car review is specific to this model, not the actual vehicle for sale. The buick rainier is the most refined of the gm suv models, and it's among the quietest suvs in its class. The rainier has a uniquely buick style and a near-luxury sensibility. Yet it still seats five and boasts an engine powerful enough to pull a boat or horse trailer. The rainier comes in just one well-equipped trim level, called cxl. Traction control is standard on 2wd models. The standard engine is gm's highly regarded vortec 4200, an inline-6 that provides an impressive 291 horsepower and 275 pound-feet of torque. Optional is the vortec 5300 v8, up-rated for 2005 to 300 horsepower and 330 pound-feet of torque. For 2006, the buick rainier gets a slight horsepower increase and other minor changes.