Donald Trump allows tax-exempt red-dyed diesel for road transport, but fails to resolve the U.S. diesel supply shortage.

US President Trump signed an executive order on Monday, temporarily allowing tax-exempt "red-dyed diesel"—originally intended for non-road uses like agriculture and mining—to enter the highway transport market, aiming to ease logistics cost pressures by cutting fuel tax burdens on trucking. Regular on-road diesel in the US currently incurs a federal excise tax of 24.3 cents per gallon, while red-dyed diesel is generally tax-exempt. Theoretically, if the policy is smoothly passed to end users, diesel costs could drop by up to around 24.4 cents per gallon. However, the measure does not increase diesel production; it only changes the fuel's tax and usage rules. The US diesel supply still faces multiple pressures. High refinery utilization rates in the US, Russia's restrictions on refined product exports, and disruptions to refined product supplies in the Middle East have kept diesel prices at elevated levels. Data from the American Automobile Association (AAA) shows that the national average retail price of on-road diesel hit a record high of $6.528 per gallon on September 22, and stood at around $6.315 per gallon on Tuesday. Meanwhile, red-dyed diesel is primarily supplied through dedicated agricultural, mining, and industrial channels, and highway truck stops generally lack the necessary storage and refueling facilities. Industry groups also warn that if large numbers of trucks switch to rural channels to source red-dyed diesel, it could squeeze fuel supplies for agricultural machinery during North America's fall harvest peak. Energy analysts note that expanding the use of tax-exempt diesel cannot alter diesel wholesale prices or refinery capacity, and can only reduce tax burdens for some end users at most; the real bottleneck in the US diesel market remains insufficient supply.