Fuel consumption of an engine is one of the most important factors for a car, the economy of a car is determined by the engine thirst. Every car driver expects to drive a car with less consumption. Differences in how a car is operated, make a different in result too, car used with maximum power and full speed for longer run is not the same as using it for city drive, which might have to make a lot of car stop. Such drive conditions will effect the fuel consumption. Control of the mixture and the timing to inject the fuel between full load and low running load or idle should be different. Because of the pollution which create more and more problem, especially from car's engine, government and environment controller have instructed designer and manufacturer of cars to commit the regulation regarding air pollution. Standard have been design to reach the condition where the components of pollutant should be minimized until it reach a zero level. To meet that expectation, a lot of changes have been made in the past until now, such as the use of light material, different type of fuel injection, using variable control of valve lift and valve timing.