M40M43B

M40M43B is a designation that can refer to several related automotive engines manufactured by BMW. Primarily, it signifies a family of four-cylinder gasoline engines that saw service in various BMW and Rover models during the 1990s and early 2000s. These engines are known for their robust construction and relatively simple design, making them reliable powerplants.

The M40M43B family includes variations in displacement, with common configurations being 1.8-liter and 2.0-liter. They are typically equipped with multi-point fuel injection and were available with either a four-speed automatic or a five-speed manual transmission. Key features of these engines include an aluminum cylinder head and an iron cylinder block.

These engines powered a range of popular vehicles, including the BMW 3 Series (E36 generation), the BMW Z3, and various Rover models such as the 200 and 400 series. While not the most powerful engines BMW ever produced, they offered a good balance of performance and fuel efficiency for their time. Over time, they were gradually superseded by newer, more technologically advanced engine designs from BMW.