Difference Between Gasoline and Petrol

Gasoline vs Petrol

Gasoline and petrol is the same thing, referred to in different names. The origin of gasoline/petrol is the petroleum oil also known as the crude oil. This fossil fuel consists of a mixture of several hydrocarbons and other impurities in gaseous, liquid, and solid states. Gasoline is one of the products isolated from the crude oil by fractional distillation and is widely consumed in the industrial world.


Gasoline is a liquid fuel derived from petroleum oil. The liquid is clear and less dense than water accounting to a relative density of nearly 0.75kg/L. The primary application of gasoline is to use as fuel in internal combustion engines of automobiles and various other machines. Gasoline is not one compound but a mixture. The contents slightly vary depending on the extraction methods, purification steps used, additives added. Gasoline contains many organic compounds mainly isooctane, butane and ethyl toluene. Apart from the main components octane enhancers like MTBE and other impurities may be present in small fractions. The hydrocarbon content may typically have hydrocarbons ranging from C4-C12.

Gasoline is highly inflammable which is why it is used in combustion engines. When the combustion occurs, hydrocarbons are converted to carbon dioxide and water in the presence of oxygen. The energy is released as heat and is around 35MJ/L. Gasoline is volatile; therefore, needs secure storage. Ideally it should be stored in an airtight container, to avoid the constituents getting mixed with moisture and oxidation. Cool temperatures are also preferred to avoid buildup of pressure due to liquid expansion. If not properly stored, solid residues form and these may corrode machines and engines. Extra care should be given if ethanol is a constituent because it absorbs more moisture.

The volatility of gasoline is changed according to the weather. In warm weather conditions, gasoline having low volatility is used; that is, hydrocarbons with high molecular weights make major part of the gasoline. In the extreme case, gasoline converts to the gaseous change and create a situation commonly known as “vapor lock” where engine fails. In cooler climates, the challenge rises due to the low/no volatility where engines fail to start.

With all the benefits gasoline brings to the industrial world, there are many environmental concerns, as well. The biggest environmental issue is the carbon dioxide emitted during combustion getting accumulated in the lower atmosphere resulting greenhouse effect. Also, when the unburned gasoline is released to air, it reacts in sunlight, to form photochemical smog. The gasoline fumes may also contain various toxic compounds dangerous to health. It has been found that unleaded gasoline alone contains more than 15 hazardous chemicals such as benzene, trimethylbenzene, naphthalene, and toluene. These chemicals are added as “anti-knocking” agents but are found to be carcinogenic.


Petrol is the same thing as gasoline.

Gasoline vs Petrol

• Gasoline is the term used in the United States and in North America but petrol is the term used in the United Kingdom and other common wealth countries.