According to a post on BMW Blog, the introduction of the new Worldwide Harmonised Light Vehicle Test Procedure (WLTP) that determines pollution and CO2 levels, would require the M3 to be fitted with a new Otto particle filter as of June first, which according to the report, would require more space in the exhaust system. Somewhat surprisingly, the requirements won't affect the M4, which will continue and eventually be fitted with the filter from June.
Initial reports have meanwhile suggested that the new 3-series, which will be based on the same CLAR platform as the 5-and 7-series, will make its world debut next year, while the M3 would follow in 2020 allegedly with either mild-hybrid setup like Mercedes-AMG's new 53 line of models or a more powerful version of the current model's S55 3.0-litre twin-turbo straight-six.
New 3-series spy image from motor1.com
