M20

M20B25 2.5 litre 12 Valve Engine

The Euro version of the M20B25 produced 170 hp with a catalytic converter and 171 without. It featured "885" head with larger ports and valves, 84 mm (3.3 in) bore, and 75 mm (3 in) stroke. Most significantly it had redesigned pistons and combustion chambers for better power, more resistance to detonation and higher thermodynamic efficiency. It was equipped with Bosch Motronic 1.1/1.3 Adaptive fuel injection. With a minor modification that adjusts the idle speed of a cold engine, the 325i fulfills Euro 2 emission requirements in Germany, resulting in a lower tax compared to Euro 1 (as of 2005).

Applications:

   * 1986–1994 E30 3 Series
   * 1989–1990 E34 5 Series
   * 1988–1991 E30 Z1

Other variations

• M20b20
• M20b23