Gasoline is a liquid composed of hydrocarbons, refined from crude petroleum, and characterized by a boiling point. It is difficult to regularly refine these oils, and their scarcity in natural resources makes it problematic to refine them. Gasoline engines produce fewer toxic emissions, like NO x , CO, and CO 2 . On the basis of economical and natural concerns, gasoline can be put back by many alternative fuels. It can be powered by alternative energy sources, like hydrogen, natural gas, ethanol, acetylene, propane, biogas, etc. The performance of these types of fuels in an internal combustion engine is very charming and appropriate for nature. Hydrogen is sustainable, and the amount of energy necessary to create hydrogen is small. Hydrogen engines are more prominent at approximately 30% compared to gasoline engines in terms of direct injection. Ethanol causes 80% less CO emissions after it has been properly blended with gasoline. Natural gas fueling stations are expanding in popularity. After the natural gas percentage is increased in the fuel, high efficiency is achieved at a sustainable performance in the 0.7−0.9 equivalent ratio. (G + 1000 g/h acetylene) has a higher brake thermal efficiency (G + 500 g/ h acetylene). These vehicles, after all, have seen considerable increases in terms of fuel economy, total performance, and substantially reduced emission standards. This study aims to compare various alternative fuels with gasoline by analyzing their availability, engine tests, toxic element emissions, price, etc. Furthermore, a selection criterion for alternative fuel is given in various measuring scales that will be helpful for choosing alternative fuels because fossil fuels are running out.
