The sports engines developed for the BMW M3 Coupé were not suitable for sale in the North American market because they were unable to comply with the applicable local exhaust emissions regulations there. This resulted in the development of two special versions that delivered 243 hp (240 US hp). The US models also differed in many technical, visual and equipment details from the ECE models. Moreover, North America had developed into one of the most robust sales markets for the BMW M3 Coupé. Production came to an end in April 1999 and a total of 21,887 units had been produced by that date. In addition, there was also the special series BMW M3 Lightweight limited to a production run of 126 units.