Perusöljyjä

Perusöljyjä are primary oils that serve as the foundational components in the formulation of lubricating oils and other industrial oils. They are distilled or synthesized from crude oil, natural gas liquids, or bio‑based feedstocks and are chosen for their baseline viscosity, chemical composition, and temperature performance. The term is commonly used in Finland and in the broader European lubricants industry to distinguish base oils from additives or finished products.

The International Lubricant Standard Association (ILSA) classifies base oils into five categories (I–V). Category I oils are low‑quality, mineral‑based oils with relatively high impurities and low performance. Category II oils, also mineral, have higher purity and are suitable for general lubrication. Category III oils are high‑quality di‑alkyl synthesized oils used in premium lubricants. Category IV oils are synthetic polyα‑olefin or ester oils that offer superior thermal stability and shear resistance. Category V oils are hybrid or entirely non‑silicone-based synthetic oils, such as polyol ester or polyether oils, designed for high‑performance applications. Perusöljyjä typically belong to categories II, III, IV, or V, depending on the intended use.

Base oils are blended with performance additives—anti‑wear, extreme‑pressure, friction modifiers, detergents, or antioxidants—to produce finished lubricants. Their manufacturing involves fractional distillation, hydrocracking, or chemical synthesis. Production processes emphasize removal of aromatics, sulfur, and nitrogen to meet environmental regulations. Regulatory considerations include limits on volatile organic compound emissions, sulfur content, and the use of bio‑based feedstocks to reduce carbon footprints. As the petroleum industry moves toward greening, perusöljyjä derived from renewable sources are increasingly explored while maintaining the mechanical stability required for advanced machinery and automotive applications.