The premium for refined diesel over crude oil in the US leaped on Sept 30 during a period of intense trading. The diesel crack spread versus Brent hit $122 per barrel as the futures contract neared expiration, though other market reports placed the spread closer to $110 per barrel during the same window.

Refining bottlenecks are now a critical driver for oil market normalization, weighing more heavily than the return of crude flows through the Strait of Hormuz. Market observers are monitoring Ukrainian drone activity and the duration of refinery turnarounds in Russia to gauge the impact on global fuel supply.