The base oil import window has narrowed to ¥210/ton — the measured landed price spread between Shanghai’s mainstream HVI150 spot and Singapore MOPS HVI150 on 20 Sep 2026. This is down ¥145 from last week’s peak of ¥355/ton, driven by Brent (-1.20% to $98.73/bbl) and WTI (-1.87% to $95.41/bbl), but partially offset by CNY strength (USD/CNY -0.03% to 6.6984), eroding ~38% of the import cost relief. At current freight and duty structure, Singapore HVI150 CFR China main port is ¥5,820/ton; Shanghai spot holds at ¥6,030/ton — a gap of just ¥210, near the breakeven threshold for importers (¥195–¥205 inclusive of customs, storage, and working capital). Refinery dynamics dominate: Sinopec Maoming and PetroChina Dalian entered Phase II of annual maintenance in September, cutting HVI unit utilization to 68% (industry norm: 82–85%). Low-sulfur distillate feedstock is being actively diverted into fuel oil blending — confirmed by today’s +0.89% rise in fuel oil futures to ¥4,297/ton. Lubricant end-demand shows no restocking impulse, yet OEM orders are increasing long-chain synthetic ester usage, pushing HVI+PAO co-blending ratios higher and further tightening domestic HVI150 liquidity. For SNSUC clients: the import hedging window is now just ±90 points; a Brent break below $97 or USD/CNY above 6.72 would close it outright. We advise offshore traders to pause new HVI150 procurement and instead draw against existing bonded warehouse digital title; importers may scale into base positions below ¥6,010/ton — contingent on either fuel oil exceeding ¥4,350/ton or asphalt rising above ¥5,480/ton, both signaling intensified distillate diversion and worsening HVI supply pressure.