The possibility of U.S. restrictions on diesel exports is creating an unusual distortion in the oil market, widening the discount of West Texas Intermediate crude to Brent as traders assess what export limits could mean for American refiners.
WTI traded as much as $12.02 per barrel below Brent on Thursday, the widest discount since May 6, according to LSEG data cited by Reuters.
The mechanism is straightforward.
If U.S. refiners cannot export surplus diesel, domestic inventories could fill quickly. Refiners would then have less incentive — and eventually less physical capacity — to process crude.
Analysts estimate the effect could be substantial.
Wood Mackenzie calculated that an export ban could redirect roughly 700,000 barrels per day of excess diesel and gasoil into storage, potentially filling Gulf Coast inventories in just over a month.
Avoiding that outcome could require refiners to reduce crude processing by more than 2 million barrels per day, equivalent to about 12% of current U.S. refinery runs.
The United States is the world’s largest diesel exporter, with net exports of approximately 1.2 million barrels per day against production of about 5.1 million barrels per day, according to Morgan Stanley figures cited by Reuters.
Those exports have become particularly important because disruption in the Middle East has reduced fuel availability elsewhere.
The policy outlook remains uncertain. The White House denied reports Wednesday that it was preparing a 90-day export ban, while Energy Secretary Chris Wright has said a ban would not solve the price surge. President Donald Trump, however, said Tuesday that he supported a ban, and Wright has contacted refinery executives about possible voluntary export restraint.
For markets, the debate matters beyond diesel prices. Reduced refinery demand would pressure U.S. crude relative to Brent, while tighter refining economics could eventually affect gasoline and other fuel prices.
