Base Oil

Base oil is the primary component of lubricants, making up 70–99% of their content. It is derived from refining crude oil (mineral base oils) or through chemical synthesis (synthetic base oils). Base oils are categorized into five groups by the American Petroleum Institute (API), based on their composition, viscosity, and refining process. They influence key lubricant properties such as viscosity, thermal stability, oxidation resistance, and performance in high/low temperatures.

Fuel Oil

Fuel oil is a fraction obtained from crude oil during refining, primarily used for heating, power generation, and marine engines. It is classified based on viscosity and use into several grades, such as diesel (light fuel oil) and heavy fuel oil (HFO). Heavier grades are less refined, more viscous, and typically used in industrial or shipping applications, while lighter grades are used in residential or transportation sectors. Environmental regulations increasingly influence its sulfur content and emissions.

Hydrocarbon Oil

Hydrocarbon oil refers to any oil composed mainly of hydrogen and carbon atoms, typically derived from petroleum. It includes a wide range of products like lubricating oils, fuel oils, and mineral oils. These oils vary in volatility, viscosity, and use depending on their molecular structure (alkanes, aromatics, etc.). Common applications include lubrication, energy generation, and chemical manufacturing. Hydrocarbon oils are non-polar, flammable, and hydrophobic.