Turbochargers are used throughout the automotive industry to enhance the output of an internal combustion engine without increasing the cylinder capacity. The application of such a mechanical device enables automotive manufacturers to adopt smaller displacement engines, commonly known as engine downsizing. Turbochargers were often used to increase the potential of an already powerful IC engine, e.g. those used in motorsport. The emphasis today is to provide a feasible engineering solution to manufacturing economics and ” greener ” road vehicles. It is because of these reasons that turbochargers are now becoming much more popular in automotive industry applications. The aim of this paper is to provide a review on the current techniques used in turbocharging to improve the engine efficiency and exhaust emissions as much as possible.