BMW N45

BMW N45 engine
BMW N45 engine
Overview
Production	2004-2011
Layout
Configuration	Inline-4
Displacement	1.6 L (1,596 cc); 2.0 L (1,997 cc)
Cylinder bore	84 mm (3.31 in); 85 mm (3.35 in)
Piston stroke	72 mm (2.83 in); 88 mm (3.46 in)
Cylinder block material	Aluminium
Cylinder head material	Aluminium
Valvetrain	DOHC, with VVT
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW N40
Successor	BMW N43

The BMW N45 is a naturally aspirated four-cylinder petrol engine which replaced the BMW N40 and was produced from 2004-2011.^[1] It was produced alongside the BMW N46 engine and only sold in several countries, where vehicle taxes favoured small-displacement engines.

The N45 is based on the N46, however it does not have balance shafts or Valvetronic (variable valve lift).^[2] As per the N42 and N46, the N45 has double-VANOS (variable valve timing).^[1] In 2007, the N45 was updated, which was called the N45N.

In 2007, the N45's successor - the BMW N43 - was introduced. However, the direct-injected N43 was not sold in countries with high-sulfur fuel, so the N45 continued to be produced alongside the N43. The N45 was phased out as new generation vehicles were released with the turbocharged BMW N13 four-cylinder engine.

Models

Engine	Displacement	Power	Torque	Years
N45B16	1,596 cc (97.4 cu in)	85 kW (114 bhp) at 6,000 rpm	150 N⋅m (111 lb⋅ft) at 4,300 rpm	2004-2011
N45B20S	1,997 cc (121.9 cu in)	130 kW (174 bhp) at 7,000 rpm	210 N⋅m (155 lb⋅ft) at 4,250 rpm	2006

N45B16

Applications:

2004–2011 E81/E87 116i
2006–2011 E90/E91 316i

N45B20S

The N45 was enlarged to 1,997 cc (121.9 cu in), to homologate the E90 320si for the World Touring Car Championship.^[3] The N45 was chosen over the N46, because its lack of variable valve lift allows higher engine speeds. Instead, the engine used dual overhead camshafts and 16 valves. The main visual difference is the carbon fiber valve cover.