A detailed study of IC engines and a novel discussion with comprehensive view of alternative fuels used in petrol and diesel engines

The main focus of this manuscript is on to discuss the alternative fuels in IC engines. Important alternative fuels for spark ignition engines are CNG, LPG or propane, alcohols, and hydrogen. Alternative fuels are to be much lower than those of gasoline and diesel-fuelled engines [Dhaliwal, B., N. Yi, and D. Checkel. 2000. ‘Emissions Effects of Alternative Fuels in Light-duty and Heavy-duty Vehicles’, SAE paper 2000-01-0692]. If there are availability problems with crude oil, due to worldwide geopolitical problems, alternative fuels can also be used as replacements. As of the year 2020, the most commonly used alternative fuel for vehicles is propane, followed by natural gas, and methanol. A number of fuels can be used as an alternative for petroleum-based diesel fuels. One alternative is biodiesel, that is, methyl ester vegetable oils, such as soybean, castor, canola, sunflower, cotton, palm, coconut, Jatropha, and algae oils. Other diesel alternative fuels are dimethyl ether (DME), and Fischer–Tropsch (F–T) fuel. In this manuscript, we discuss the alternative fuel which is most suit for SI engine and CI engine.