N150 base oil–WTI spread widens to CNY 820/t (+12.3%), the widest in 6 months; fuel oil futures surge 2.54% to CNY 4,476/t, lifting blending costs amid refinery turnarounds. SNSUC data shows N150 spot premium at Shanghai FTZ bonded warehouses up to +CNY 180/t — import arbitrage is now economically viable.