· Global base oils prices hold firm or rise vs feedstock/competing fuel prices.· Base oils margins hold firm at time of year when supply-demand fundamentals are typically weaker.· Firm base oils margins instead point to stronger-than-usual fundamentals for time of year.· Firm base oils margins incentivize refiners to maintain or raise output.· Fundamentals would need to be stronger than usual to absorb steady or higher output.· Alternative is rise in surplus supply.· FOB Asia base oils prices rise vs Singapore gasoil prices, especially for light grades..· FOB Asia Group I SN 500 price-premium to gasoil rises to highest since early-June 2025, narrows gap to Group II heavy-neutrals price-premium.· Strength of price margins incentivize refiners to maintain or raise output of heavy grades.· FOB Asia Group II N150 price-premium to gasoil rises to highest since H2 May 2025, outpacing rise in Group II heavy-grade price-premium.· Rebounding N150 price-premium adds to incentive for refiners to focus on maximising base oils output..· China’s domestic Group II N150 price-premium to Shandong diesel prices holds steady at low level, especially compared with year-earlier levels..· Steady price-premium follows surge in premium in early-Aug 2025, at a time when domestic demand typically gets boost from round of stock-replenishment.· Any extension of price-premium holding at current levels would point to relatively weak supply-demand fundamentals.· Dynamic would suggest seasonal rise in demand is weaker than usual..· CFR India Group II N70 price-premium to Singapore gasoil price extends rise to highest since end-May 2025..· Speed and strength of rebound in price-premium points to sufficiently-strong demand that counters impact of lower gasoil prices.· Higher N70 price-premium facilitates arbitrage to move more supplies to India, incentivizes Asia’s refiners to boost output of very-light grades..· Europe’s domestic Group I brightstock price-premium to vacuum gasoil (VGO) stays unusually high in Q3 2025..· Brightstock price-premium widens even more its gap vs Group I SN 500 and especially SN 150 price-premium.· High brightstock price-premium points to supply-demand fundamentals that remain as tight in Q3 2025 as earlier in the year, even at a time when demand faces seasonal slowdown..· US domestic Group II heavy-grade price-premium to VGO unusually rises more than rise in Group II light-grade premium to VGO..· US Group II heavy-grade price-premium to VGO falls more than light-grade-premium to VGO since peaking this year in early-May 2025.· Stronger rise in Group II heavy-grade price-premium to VGO in past week reverses that trend, at least temporarily.· Any extension of trend would add to incentive for refiners to maintain steady base oils output..Asia base oils demand outlook: Week of 18 August.Asia base oils supply outlook: Week of 18 August.Base Oil News stories and analysis also available on ICIS platform