Whether smoothly idling or accelerating to top speed: every BMW engine has its own signature sound, accentuating the unique character of the vehicle. Acoustic engineers at the BMW research centre refine the characteristics of the sound of each engine. Their work ensures that the BMW 650i sounds powerful and cultivated. From sight of its exclusive design and the feel of high-quality materials, to the unique and compelling sound of its precisely-engineered powerplant: driving a BMW is truly an experience for all the senses.