Difference Between Gasoline and Diesel

Gasoline vs Diesel

Gasoline and diesel are the most common automobile fuels and have a never-ending demand. Both of the fuels have pros and cons of using it. In terms of environmental safety, both are harmful. However, they have become essential requirements in today’s world.


Gasoline is a mixture of a large number of hydrocarbons, which have 5-12 carbons. There are aliphatic alkanes like heptane, branched alkanes like isooctane, aliphatic cyclic compounds, and small aromatic compounds. But there are no alkenes or alkynes other than these hydrocarbons. Gasoline is a natural by- product of petroleum industry, and it is a non renewable source. Gasoline is produced in the fractional distillation of crude oil. When they are separated based on their boiling points, the low molecular weighted compounds in the gasoline are collected in the same range. Gasoline, also known as petrol in some countries, is a fuel used in internal-combustion engines of vehicles. The combustion of gasoline produces a high amount of heat energy and carbon dioxide and water. Additional compounds have mixed with gasoline in order to enhance its usage in engines. Hydrocarbons like isooctane or benzene and toluene are added to gasoline, to increase its octane rating. This octane number measures the ability of an engine to cause self ignition in the engine cylinders (which causes knocking). When gasoline and air mixture are caught in premature ignition, before the spark is passed from the spark plug, it pushes against the crankshaft producing a knocking sound. Due to this knocking, the engine tends to overheat and loose power. Therefore, it damages the engine in the long run. Therefore to reduce this, octane number of the fuel has to be increased. Other than adding hydrocarbons as stated above, the octane number can also be increased by adding certain lead compounds. This will increase the octane number; thus, gasoline will be more resistant to the self ignition which causes knocking. Gasoline prices are largely varying over time with the price of crude oil. Since gasoline has become a primary need, in most of the countries, the variation in oil prices affects the country’s economy too.


Diesel is also an automobile fuel which is a by- product of petroleum distillation. Diesel is oil like, denser and has a higher boiling point than water. Diesel consists of hydrocarbon having longer carbon chains where they have carbons from 8 to 21. The compounds in diesel include paraffins, isoparaffins, napthenes, olefins and aromatic hydrocarbons. Depending on the usage, diesel can be categorized into different grades. (Ex: 1-D (S15), 1-D (S500), 1-D (S5000), 2-D (S15), 2-D (S500), 2-D (S5000) and 4-D). Cetane number of diesel is a property for end users to look at. It measures the ignition quality of the fuel. Cetane number is different from the octane number of gasoline. For instance, higher the cetane rate, the more easily it ignites. Although the combustion of diesel results in low amounts of carbon monoxide, carbon dioxide, they give out high amounts of nitrogen compounds and particulate matter, are responsible for acid rain.


What is the difference between ?

• Diesel evaporates slower than gasoline.

• Diesel is oily like ,and smells differently than gasoline.

• Diesel consists of hydrocarbons which have more carbon numbers than gasoline. So the molecular weight of diesel is higher than gasoline. Therefore, diesel is less volatile and has a higher boiling point than gasoline.

• Diesel is cheaper than gasoline, but gasoline is cleaner, and more environmental friendly.

• Gasoline can be rated according to the octane number, whereas diesel is rated according to the cetane number.