The BMW 501 A and BMW 501 B represented the first attempt by BMW in spring 1954 to address the criticism levelled at the company about the lack of engine power and the high price of the new BMW 501. The increased power output resulted in the service life of the engine suffering considerably and this led to numerous complaints as a result. These entailed major financial losses and also impacted very negatively on the image of the brand. The two models affected by this were therefore already replaced by a version with the designation BMW 501 six-cylinder as early as 1955. The increase in the displacement to 2077 cc increased the service life and improved torque development with the same power.