Gasoline vs. Petrol

What's the Difference?

Gasoline and petrol are essentially the same thing, with the only difference being the terminology used in different regions. Gasoline is the term commonly used in the United States and Canada, while petrol is the term used in most other English-speaking countries, including the United Kingdom, Australia, and New Zealand. Both gasoline and petrol are fuels derived from crude oil and are used to power internal combustion engines in vehicles. They have similar chemical compositions and properties, making them interchangeable in terms of their usage and functionality.


Photo by Dawn McDonald on Unsplash
OriginDerived from crude oilDerived from crude oil
Commonly used inNorth AmericaEurope, Asia, Australia
Term used inUnited States, CanadaUnited Kingdom, India, Australia
Chemical compositionPrimarily hydrocarbonsPrimarily hydrocarbons
Octane ratingMeasured in AKI (Anti-Knock Index)Measured in RON (Research Octane Number)
ColorColorless or light yellowColorless or light yellow
UsageUsed as fuel for internal combustion enginesUsed as fuel for internal combustion engines
AvailabilityWidely available in North AmericaWidely available in Europe, Asia, Australia
StorageStored in underground tanks at gas stationsStored in underground tanks at petrol stations
Photo by Juan Fernandez on Unsplash

Further Detail


Gasoline and petrol are two terms commonly used to refer to the same fuel that powers most vehicles around the world. While the terms are often used interchangeably, there are some subtle differences between them. In this article, we will explore the attributes of gasoline and petrol, including their composition, octane ratings, availability, and environmental impact.


Both gasoline and petrol are derived from crude oil through a refining process. They are mixtures of hydrocarbons, which are compounds made up of hydrogen and carbon atoms. However, the specific composition of gasoline and petrol can vary slightly depending on the region and the refining techniques used.

Gasoline typically contains a higher percentage of aromatic hydrocarbons, such as benzene, toluene, and xylene, which contribute to its higher energy content. On the other hand, petrol often contains a higher proportion of aliphatic hydrocarbons, such as pentane and hexane, which provide better cold-start performance.

Both fuels also contain additives, such as detergents and corrosion inhibitors, to improve engine performance and protect against wear and tear. These additives may vary between gasoline and petrol brands, but their overall purpose remains the same.

Octane Rating

The octane rating is a measure of a fuel's ability to resist knocking or pinging during combustion. Knocking occurs when the air-fuel mixture in the engine's cylinders ignites prematurely, leading to inefficient combustion and potential engine damage.

In general, gasoline tends to have a higher octane rating compared to petrol. Gasoline typically has an octane rating between 87 and 93, while petrol commonly has an octane rating between 91 and 95. The higher octane rating of gasoline allows for higher compression ratios in engines, which can result in increased power and efficiency.

However, it's important to note that octane ratings can vary between different countries and regions. For example, in some countries, petrol may have a higher octane rating than gasoline due to different refining processes and regulations.


The availability of gasoline and petrol can vary depending on the country and region. In the United States and Canada, the term gasoline is predominantly used, while petrol is more commonly used in countries like the United Kingdom, Australia, and New Zealand.

Additionally, the composition and quality of gasoline and petrol can differ between countries due to variations in refining standards and regulations. This can impact the performance and emissions of vehicles when using fuel from different regions.

It's worth noting that some countries have embraced alternative fuels, such as ethanol-blended gasoline or biofuels, to reduce dependence on fossil fuels and lower greenhouse gas emissions. These alternative fuels may have different attributes and availability compared to traditional gasoline and petrol.

Environmental Impact

The environmental impact of gasoline and petrol is a significant concern due to their contribution to air pollution and greenhouse gas emissions. Both fuels release carbon dioxide (CO2) when burned, which is a major contributor to climate change.

However, petrol tends to have slightly lower carbon emissions compared to gasoline. This is primarily due to the differences in their composition, with petrol containing a higher proportion of aliphatic hydrocarbons that burn more efficiently. Additionally, petrol engines often have better fuel efficiency, which can further reduce carbon emissions.

Nevertheless, both gasoline and petrol contribute to air pollution through the emission of nitrogen oxides (NOx), volatile organic compounds (VOCs), and particulate matter. These pollutants can have detrimental effects on human health and the environment, leading to respiratory issues and the formation of smog.

To mitigate these environmental impacts, governments and automotive manufacturers are increasingly promoting the use of electric vehicles and exploring alternative fuels, such as hydrogen and renewable energy sources, to power transportation and reduce reliance on gasoline and petrol.


While gasoline and petrol are often used interchangeably, there are subtle differences in their composition, octane ratings, availability, and environmental impact. Gasoline typically contains more aromatic hydrocarbons, has a higher octane rating, and is more commonly used in the United States and Canada. Petrol, on the other hand, often contains more aliphatic hydrocarbons, has a slightly lower octane rating, and is more commonly used in the United Kingdom, Australia, and New Zealand.

Both fuels have a significant environmental impact due to their carbon emissions and air pollutants. However, petrol generally has lower carbon emissions and better fuel efficiency. As the world moves towards a more sustainable future, the development of alternative fuels and the adoption of electric vehicles are crucial steps in reducing our dependence on gasoline and petrol and mitigating their environmental impact.

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