Find your 2.5 Liter engine

2.5-Liter Engines: BMW manufactured a few notable 2.5-liter engines under the M54, M52, and the N52 series of engines. These engines vary widely in design from all-aluminum configurations to cast-iron block/ aluminum cylinder heads and even to a magnesium-aluminum mix.

• M52TUB25 - This 2.5 BMW engine is a straight 6-cylinder engine with a cast-iron block and an aluminum dual overhead cam (DOHC) cylinder head. This version of the 2.5-liter inline 6-cylinder BMW engine featured a variable valve timing (VVT) system that was dubbed “double VANOS”. This engine was used in the production of the 1998-2000 BMW 323i, the 1998-2000 BMW 523i, and the 1998-2000 BMW Z3 2.3i.
  
  
• M54B25 - The M54B25 engine is the direct replacement of the previously used M52TUB25 engine. The upgrades included in this 2.5 BMW engine for sale are an aluminum block instead of cast iron, a better engine management system, and a more efficient intake manifold. This engine retains the double VANOS variable valve timing (VVT) system and is rated at approximately 189 horsepower from the factory. This BMW engine was used in the 2000-2002 BMW Z3 2.5i, 2000-2006 BMW 325i/ 325xi/ 325ci, 2000-2002 BMW Z3 2.2i, 2003-2005 BMW Z4 2.2i, and the 2003-2005 BMW 520i.
  
  
• N52B25 - The N52 engine series replaced the older M52 and M54 engines and included an all-new magnesium/aluminum mix which allowed for a much lighter engine. This 2.5-liter inline 6-cylinder engine also featured a new 3-stage variable-length intake manifold which allowed for adjustable airflow depending on the engine’s environment. This 2.5 BMW straight-6 engine was rated at either 174 hp, 201 hp, or 215 hp depending on the year and the model it was in. This engine was used as a 2004-2007 BMW 523i engine, the 2006-2011 BMW Z4 engine, the 2010-2011 BMW 523i engine, the 2005-2010 BMW X3 engine, the 2005-2010 BMW 525i engine, and the 2005-2011 BMW 325i engine.
  
  
• M52B25 - The M52B25 motor is a 2.5-liter inline-6 with a compression ratio of 10.5:1. It produced 168 horsepower stock and was used in the 1995-1998 BMW 323i/ 323ci/ 323ti and the 1999-2000 BMW Z3 2.0i.
  
  
• M52TUB25 - This 2.5 BMW straight-6 engine is found in the 1998-2000 BMW 323i/ 323ci, 1998-2000 BMW 523i, and the 1998-2000 BMW Z3 2.3i. It was rated at 168 horsepower in its stock form. This engine did include the double VANOS variable valve timing (VVT) system.