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.
Applications: 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.
The main visual difference is the carbon fiber valve cover.