A rolling stone gathers no moss. Trite, but true, especially when it comes to BMW. Just two years after launching the redesigned BMW 5-Series, Germany's purveyor of ultimate driving machines debuts new inline six-cylinder engines, a new all-wheel-drive system, and a new station wagon variant of the 5-Series for 2005.

BMW's new family of inline six-cylinder engines supplies more power, greater efficiency, and lower mass than ever before. BMW 525i models receive a new 218-horsepower, 2.5-liter inline six that cranks out 184 lb.-ft. of torque between 2,750 and 4,250 rpm. BMW 530i models get a 258-horse motor displacing 3.0 liters and developing 221 lb.-ft. of torque between 2,500 and 4,000 rpm. Thanks to engine blocks constructed of aluminum and magnesium, these new engines are also lighter than before, helping to reduce curb weight. In fact, BMW claims that they are the lightest vehicles in their class.