ABSTRACT
While the latter is used for all our heavy vehicles in railway transport, in tractors, etc. the former is used for all light vehicles like cars, three wheelers and two wheelers. Overall efficiency of a gasoline engine is lower than that of a diesel engine; still it offers certain advantages due to its operation based on gasoline, a light fuel. The advantages are in the form of quick start, fast acceleration, no large emission of particulate matter (PM), no frequent major engine overhauling requirement, etc. One of the major concerns of the diesel
engine is the emission of 100-200 times smaller sized PM than that in the gasoline engine exhaust. Gasoline gives the advantage of making possible two stroke engines for motor bikes, scooters, etc. without the need of cumbersome valve mechanism. The demand for light vehicles continues to grow faster than for heavy vehicles. If the diesel and petrol prices are near to each other as is the case in other countries, the tendency of having diesel engines in cars would not be there. The recent price trends show that the gap between the prices of petrol and diesel would close. The demand for auto cycles is growing very fast. With increase in trade and urbanisation, a larger segment of population is finding it essential to use two wheelers. The per capita income is growing, and there is a corresponding increase in the use of cars also. The fuel for such engines (spark ignition) is petrol derived by distilling crude oil taking out from the petroleum reserves. It is composed of hydrocarbons which give it a high calorific value of above 10,000 kcal/kg. Gasoline has all the desirable properties for storage, ignition, combustion and handling. However, as narrated earlier, gasoline has two drawbacks which every petroleum derived fuel has namely that it is derived from a depleting resources and that its engines’ emission increases the level of NOx, CO2, particulate matter and hydrocarbons in the atmosphere. For the emission of greenhouse gases (GHGs) as NOx and CO2, it is a major contributor to climate change, the greatest concern of the present day.
