Japan’s base oils production fell in August to the lowest in more than a decade even as the country’s total refined products output rose.Base oils output slid to less than 133,000 kilolitres (118,000 tonnes) in August, government data showed..The volume fell for the twenty-eighth time in twenty-nine months from year-earlier levels to the lowest since before 2010.Output fell in August despite the lack of any scheduled plant-maintenance work. Even when there is maintenance work, the size of the fall in production is typically smaller.Base oils production also fell in August despite a rise in Japan’s total refined products output to a seven-month high.The diverging trends pointed to moves to cut base oils supply and instead boost output of other products like middle distillates and bitumen..A firm diesel premium to crude oil boosted the attraction of producing more middle distillates.The start-up of new base oils production capacity in Singapore in September boosted the attraction of focusing on other products like bitumen, which share some of the same feedstocks as Group I base oils.Japan’s asphalt output rose in August for the seventh time in eight months from year-earlier levels and exceeded the country’s base oils output for the second month in a row.Asphalt output previously exceeded base oils production just four times in the three years to June 2025.Any extension of those moves to produce other products could prolong a steep fall in Japan’s base oils output in recent years.Lower output would partially cushion the impact of the expected rise in base oils supply from Singapore in the coming months.Lower output would also prolong a sustained fall in Japan’s base oils exports, especially to southeast Asia.The trend could speed up a switch by regional buyers to using Group II base oils instead of Group I, and to using a new heavy-grade Group II product from Singapore as an alternative to Group I brightstock..ExxonMobil ships Group II base stocks from new Singapore units.Japan’s July base oils exports fall.Thailand’s July base oils output falls.Base Oil News stories and analysis also available on ICIS platform
