The BMW N53 is a naturally aspirated straight-six petrol engine which was produced from 2006 to 2013. The N53 replaced the BMW N52 and was released in 2006 in the post-facelift E60 5 Series. BMW never sold the N53 engine in North American, Australian and Malaysian vehicles, due to the high sulphur content of the fuel available in these markets. Instead, these regions continued to use its predecessor, the N52 engine. There is no BMW M version of the N53. The BMW N54 turbocharged straight-6 engine was produced alongside the N53.