In recent years, legislative and market requirements have driven the need to reduce fuel consumption while meeting increasingly stringent exhaust emissions. This trend has dictated increasing complexity in automotive engines and new approaches to engine design. A key research objective for the automotive engineering community has been the potential combination of gasoline-engine specific power with diesel-like engine efficiency in a cost-competitive, production-feasible power train. One promising engine development route for achieving these goals is the potential application of lean burn direct injection (DI) for gasoline engines. In carburetors the fuel is sucked due to the pressure difference caused by the incoming air. This will affect the functioning of the carburetor when density changes in air are appreciable. There was a brief period of electronically controlled carburetor, but it was abandoned due to its complex nature. On the other hand in fuel injection the fuel is injected into the air.