OEM BMW M20B25 2.5L Engine / Motor – E30 325i / 323i / 320i / Alpina Applications

Genuine BMW M20B25 2.5-liter inline-6 engine, the iconic powerplant of the E30 325i and related models.

This smooth-revving SOHC 12-valve six-cylinder is renowned for its refined character, strong mid-range torque, and classic BMW inline-six soundtrack. Widely used across the E30 range and adapted in various Alpina and performance applications, the M20B25 remains one of the most popular and versatile engines from the era.

Key specifications

• Engine code: M20B25
• Displacement: 2.5 L (2494 cc)
• Configuration: Inline-6, SOHC, 12-valve
• Power: approximately 168–170 hp (depending on market and tuning)
• Torque: approximately 164 lb-ft (222 Nm)
• Fuel system: Bosch Motronic

Ideal as a complete replacement engine or a foundation for a high-quality rebuild, swap, or performance build. The M20B25 delivers the authentic driving experience that made the E30 325i a standout model.

Common fitment

• BMW E30 325i / 325is
• BMW E30 323i / 320i (with appropriate adaptations)
• Select Alpina models based on the M20 platform
• Other compatible chassis (verify exact year, market, accessories such as intake, exhaust manifolds, sensors, and wiring for your specific application)

Perfect for owners seeking a genuine OEM M20B25 engine to restore or upgrade a classic E30 or related BMW.