The June 12, 2021 notice pulled imported fuel oil, diluted bitumen and mixed aromatics into the consumption-tax schedule. Fuel oil is taxed at 1.2 yuan/liter; converted by density, that is a bit over 1,200 yuan per tonne, carved straight out of delivered cost.

In prior years, independent refiners used diluted bitumen — a product that did not consume crude-import quotas — as a back-door feedstock to lower processing cost. Once the tax landed, that cheap route closed; diluted bitumen's delivered economics shrank sharply, and some refiners had to return to fighting for formal crude quotas or accept higher compliant feedstock cost.

For a structure like SNSUC's — supplying through an offshore SPV as an intermediary — the tax actually draws a cleaner line: we provide formal crude with complete origin and quality certificates, not tax-arbitrage feedstock. The delivered-cost formula for the seven transshipment grades (ESPO, Dubai, Oman, Urals, Basrah Light, Bonny Light, Lula) is already built on net price plus freight and is unaffected by this levy aimed at substitute feedstocks.

Two variables to track: whether the gap between diluted-bitumen delivered duty-paid price and formal crude reopens (a widening gap revives grey feedstock), and whether refinery runs step down again on higher feedstock cost. Both signals set the heavy-product supply rhythm for the second half.