Among the six-cylinder models of the BMW 5 Series Sedan, the BMW 523i represented the "sweet spot." With an engine displacement of 2.5 liters and a peak power of 170 hp, the engine characteristics of the BMW 523i were optimized for the consistent delivery of high torque rather than maximum performance. Thus, the BMW 523i was the ideal choice for comfort-oriented frequent drivers who also paid attention to the economy of their vehicle.