The BMW N45 is a naturally aspirated four-cylinder petrol engine which replaced the BMW N40 and was produced from 2004-2011. It was produced alongside the

BMW N46 The BMW N46 is a naturally aspirated inline-four piston engines 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 suc ...

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 The Valvetronic system is a BMW variable valve lift system which, in combination with VANOS, allows infinite adjustment of the intake valve timing and duration. The system claims to improve fuel economy and emissions, and negates the need for ...

(variable valve lift). As per the N42 and N46, the N45 has double-VANOS (variable valve timing). 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

N45B16

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

N45B20S

The N45 was enlarged to , to

homologate Homologation (Greek ''homologeo'', ὁμολογέω, "to agree") is the granting of approval by an official authority. This may be a court of law, a government department, or an academic or professional body, any of which would normally work fr ...

the E90 320si for the

World Touring Car Championship The FIA World Touring Car Championship was an international touring car championship promoted by Eurosport Events and sanctioned by the Fédération Internationale de l'Automobile (FIA). It has had several different incarnations, including a sin ...

. 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 Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

valve cover. Applications: *2006 E90 320si (Limited production model)

References

{{DEFAULTSORT:Bmw N45 N45 Straight-four engines Gasoline engines by model

Models

N45B16

N45B20S

See also

References