Type‑based segmentation further refines the market picture by distinguishing the chemical foundations of finished lubricants. Mineral‑base oils, derived from crude distillation, are classified into Group I, II and III, with Group III offering the highest viscosity index and oxidative stability; together they capture roughly 55 % of refinery output, driven by cost‑sensitive automotive and industrial users. Synthetic‑base oils, including polyalphaolefins (PAO), esters, and silicones, deliver superior low‑temperature fluidity and high‑temperature endurance, commanding about 30 % of the market, especially in aviation, high‑performance automotive and marine propulsion. Semi‑synthetic blends, which combine mineral and synthetic fractions, occupy the remaining 15 % and serve applications that require a balance of performance and price, such as certain gear and hydraulic oils. This type taxonomy clarifies how each base‑stock category contributes to overall capacity utilization and profit margins, reinforcing the relevance of precise Lube Oil Refinery segmentation for strategic planning.