Difference Between Petrol and Diesel
Petrol and diesel are the most commonly used fuels in our cars. Yet many are not aware of the differences between the two although the price difference and the mileage that these two give different petroleum products are too well known. This article intends to highlight the difference between petrol and diesel to allow people to go for a fuel that goes with their requirements.
Petrol, also known as gasoline in Western countries and diesel are obtained from crude oil that is pumped out of the oil sources. Crude oil is black in color and it contains various hydrocarbons that differ in composition. The simple hydrocarbons such as CH4, C2H6, C3H8 and C4H10 are all gases are easily collected and used as solvents in paints and also used for dry cleaning. Of higher hydrocarbons from C5 to C12 are heavier and have longer chains. They are liquid at room temperature and collected by distillation of crude oil. Petrol is mainly composed of C5 to C12 hydrocarbons that are mixed together to make a flammable liquid used as fuel in cars. A typical gas mixture contains paraffins, naphthenes, aromatics and olefins. The diesel is composed of about 75% saturated hydrocarbons and aromatic hydrocarbons by 25%. Both petrol and diesel are derived from crude oil but at different temperatures. While gasoline or petrol is derived between 35 degrees and 200 degrees centigrade, diesel is separated in the range of 250-350 degrees centigrade.
Diesel is composed of hydrocarbons with longer carbon chains when compared to petrol and this makes it less volatile. It is also because of various additives in diesel. From the point of view of the energy content, petrol has about 34.6 mega joules per liter while diesel fuel contains about 38.6 mega joules per liter. This means that the diesel has a higher power than gasoline and that is precisely why it is used in heavy vehicles which need more power. The diesel gives more mileage than petrol by almost 50that is almost 50%. This is probably why people prefer diesel engines.
In some countries like India, diesel prices are subsidized as it is mainly used for transport. This makes it less expensive than gasoline or petrol. But in the Western world, is priced at par with gasoline or petrol, but people still prefer diesel over petrol because it gives more mileage.