Guide to BMW Engine Identifier Numbers

BMW used the suffix "M" followed by a number to first identify their various engine types beginning with the advent of BMWs four-wheeled endeavours in the 1930s. Subsequently, many years later as the "M" division began producing sporting variants of standard BMW cars, the suffix "S" was used to denote those highly tuned engines. "M" suffixes were replaced with "N" in the early 2000's as new engine designs emerged, and lately, "B" has also come into use.

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