Gasoline and Diesel are both types of fuel used to power all types of vehicles and equipment. Gasoline and Diesel are also often sold at the same gas station, so what is the difference between gasoline and diesel? For this discussion we will compare the similarities and differences between petroleum based gasoline and diesel. There are different types of diesel fuel available, like bio-diesel, which I will discuss in a later Difference Between post.
Difference in Refining
The difference between gasoline and diesel begins with how it’s produced. Petroleum is refined to produce gasoline and diesel, but the type of fuel is decided at different refining points. Crude oil, which is the thick black stuff you see exploding from oil wells, is refined in a chemical process. Think of the process as like a tower and time spent refining yields a different product from the same crude oil. During the process the crude oil is refined into Heavy Gas Oil, then Lubricating Oil, and then into Diesel.
Diesel fuel takes less time and is lower on the refining process, which typically leads to it being lower in price. The next step of the refining process produces Kerosene and then finally Gasoline which is used in your car. This is a simplification of the refining process, which also includes removing impurities, and lastly involves treating the fuel with additives, generally to increase octane rating.
Typically when fueling up at the gas station you will notice different octane rated gasoline. Diesel fuel is not measured by octane rating, rather by a cetane rating. The ratings are similar in that they are used to rate the combustion quality of the fuel.
Diesel and gasoline are not interchangeable. Gasoline engines are specifically designed to operate with gasoline properties and diesel engines are designed to operate under diesel fuels properties. Using diesel fuel in a gasoline engine and vice versa could damage your engine.
In addition, gasoline will gel at a much lower temperature than diesel fuel. This is why during the winter time, diesel vehicles will some times be plugged in, to allow a heater to keep the fuel above it’s gelling temperature. This core heater will allow for a much easier start in frigid temperatures.
This has been a post into a series of articles on explaining entry level questions to automotive enthusiasts.
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