Basket Case – The $100/bbl Diesel Crack, or How 2026 Exposed the Fragility of Global Refining

For many, 2026 will be remembered as the year that diesel cracks topped the century mark ($100/bbl) for the first time. On August 17, the U.S. Gulf Coast diesel crack spread (vs. WTI Cushing) surpassed that sky-high level, and although it has since fallen into the $90s/bbl, it remains at levels never seen before, even exceeding those during the post-COVID boom year of 2022. In today’s RBN blog, we examine the various factors driving this run-up and what they say about the overall physical refined products market.

Let’s start with some background about where things stand today. The global crude markets are not short of crude in the traditional sense (despite various geopolitically caused constraints). Instead, the world is struggling to refine enough crude oil into middle distillates to satisfy demand. That distinction is critical. According to the EIA’s Weekly Petroleum Status Report (WPSR) for the week ended August 21, distillate inventories fell for a fourth consecutive week, dropping to just above 103 MMbbl (see our Crude Billboard for more details). Distillate stocks are on track for their lowest end-of-month level since April 2005, and are the lowest they have been in the month of August since 1951.

The events of 2026 have created a series of simultaneous disruptions to global refining capacity and refined-product flows. Middle Eastern refineries have been affected by damage inflicted during the Iran conflict and disruptions around the Strait of Hormuz, while Russian refining and exports have been repeatedly set back by Ukrainian drone attacks. This is all coming at a time when global refining capacity was already tight due to a number of permanent shutdowns (many during the COVID years) and limited new capacity coming online. As a result, even as U.S. refiners have been running exceptionally hard and exporting record volumes, the world supply of middle distillates (including diesel and jet fuel) is playing catch-up with demand, resulting in a market in which every additional diesel barrel has become extremely valuable.

A crack spread measures the difference between the value of refined products and the crude oil used to produce them. A $100/bbl diesel crack (right end of orange line and left axis in Figure 1 below), therefore, does not mean a refinery is earning $100/bbl in net profit. Refiners still have operating expenses, transportation costs, financing costs, hedging effects and the economics of the other products produced by the refinery. Instead, it means that the market value of diesel relative to crude has become extraordinarily high. That distinction gives us the first major clue about what is happening. If crude (blue line and left axis) is expensive because the world is short of barrels, crude prices should be doing most of the work. But when diesel prices (green dashed line and right axis) rise dramatically relative to crude, the problem is further downstream.