Regional rates differ due to local refining capacity, import dependence, shipping distance, and regulatory requirements. Oil specification affects price through base stock quality, inhibitor package, oxidation stability, and required test certification. Ester and silicone oils generally command higher prices and may have fewer suppliers in some regions, increasing lead time and cost. Utilities that require strict documentation, traceability, and compliance with specific standards may pay more than industrial buyers using generic grades. Currency and duties also impact regions where oil is imported rather than produced locally.