The BMW N46 is a naturally aspirated inline-four petrol piston engine which replaced the BMW N42 and was produced from 2004 to 2015.

The N46 serves as the basis for the smaller BMW N45 engine (which does not have Valvetronic).

In 2007, the N46's successor - the BMW N43 - was introduced. However, the direct-injected N43 was not sold in countries with high-sulfur fuel, so the N46 continued to be produced alongside the N43. The N46 continued production until 2015, when the last N46 models were replaced by the BMW N13 turbocharged four-cylinder engine.

Design Compared with its N42 predecessor, the N46 features a revised crankshaft, intake manifold and valvetrain. In 2007, the N46 was updated, which was known as the N46N. Changes included the intake manifold, exhaust camshaft and the engine control unit was changed from Bosch Motronic version ME9.2 to version MV17.4.6. The redline is 6,500 rpm.

Versions VersionDisplacement Power Torque Year N46B18 at 5,500 rpm at 3,750 rpm 2004 N46B20U1 at 5,750 rpm at 3,250 rpm 2005 N46B20U2 at 5,750 rpm at 3,250 rpm 2007 N46B20U0 at 6,000 rpm at 3,750 rpm 2007N46B20O1 at 6,200 rpm at 3,600 rpm2004 at 3,750 rpm N46NB20 at 6,400 rpm at 4,100 rpm2007

N46B18 The N46B18 has a displacement and produces and .

Applications: 2004-2005 E46 316i/316ti

N46B20U0 The N46B20U0 produces and .

2007-2008 E90 318i

N46B20U1 The N46B20U1 produces and .

Applications: 2005-2007 E87 118i 2005-2007 E90/E91 318i

N46B20U2 The N46B20U2 produces and . It was used instead of the N43 engine in countries with high-sulfur fuel.

Applications: 2007-2011 E81/E87 118i 2007-2013 E90 318i

N46B20A The N46B20A produces and .

Applications: 2004-2006 E46 318i, 318Ci and 318ti

N46B20O1 The N46B20O1 produces and . On models with secondary air injection, peak torque occurs at 3750 rpm instead of 3600 rpm.

Applications: 2005-2006 E46 318Ci 2004-2007 E83 X3 2.0i 2005-2008 E85 Z4 2.0i 2004-2007 E87 120i 2005-2007 E90/E91 320i

N46NB20 The N46B20 produces and . It was used instead of the N43 engine in countries with high-sulfur fuel.

Applications: 2007-2011 E81/E82/E87/E88 120i 2007-2013 E90/E91/E92/E93 320i 2007-2010 E60 520i 2009-2015 E84 X1 sDrive18i / xDrive18i 2007-2010 E83 X3 2.0i

N46B20 engine number key code:

See also BMW List of BMW engines

References