2.2.II. Autoignition Autoignition can be defined as the situation where the fuel in a combustion chamber burns automatically without external causes such as a spark plug, and this is caused by the extremely high temperature and pressure inside the chamber. Furthermore, the fuel inside the combustion chamber will not burn at the right time and combustion cannot be as efficient as if it burned at the right time. Consequently, this problem will have negative effects both economically and environmentally (Willard, 1997).2.2.III. Incomplete combustionThis situation usually occurs if there is an air reserve inside the combustion chamber or if oxygen is low. In this situation carbon monoxide, carbon and water are produced. Furthermore, there will be two problems with this type of combustion which will produce a poisonous gas, carbon monoxide, and the fuel will not burn efficiently (Bbc.co.uk,