In the 31 August morning session Brent held at $89.27/bbl (-0.01%) and WTI at $84.40/bbl (-0.02%), leaving crude broadly steady, yet downstream products diverged: fuel oil fell 0.54% to RMB 3,650/t while bitumen rose 0.30% to RMB 4,610/t, widening the spread to RMB 960/t. We unpack the tug-of-war between off-season bunker demand and peak road construction, and set out a staged price-locking approach.