On October 5 the President signed an executive order, "Emergency Tax Relief on Diesel Fuel", with diesel at $6.199 a gallon, the U.S. average that week. It does two things for anyone with a diesel pickup. It tells the Treasury to defer the federal excise tax on diesel incurred from October 5 to December 31, 2026. And it tells the IRS not to penalize anyone for selling or using dyed diesel on the highway during the same period.

Dyed diesel is the red, untaxed fuel sold for farm equipment, generators and construction machines. Until now, finding it in a road vehicle's tank meant a fine. For the rest of 2026, at the federal level, it does not.

What the order does not change

Three things are worth knowing before you fill up with red.

It is federal only. States tax diesel too, and many enforce their own dyed-fuel rules. The order asks the White House to encourage states to follow, but it cannot make them. A state inspector can still treat red fuel in a pickup as tax evasion until your state says otherwise.

It is a deferral, not a refund. The tax is deferred "without any penalties, interest" and the Treasury is told to explore ways, including legislation, to forgive it. Exploring is not forgiving. Whoever owes the tax, usually the seller, may still owe it later.

It does not change the fuel. The order is about tax. It says nothing about what is in the tank.

The order changes what red diesel costs. It does not change what is in it.

What the manuals actually ask for

That last point is the one that matters to the engine. Ford's 2025 Super Duty owner's manual asks for ultra-low sulfur diesel, number 1-D or 2-D, with a maximum of 15 ppm sulfur, meeting the ASTM D975 standard, or biodiesel blends up to B20 meeting ASTM D7467. It warns that fuel with 16 to 500 ppm sulfur can damage the emission control and aftertreatment systems, "potentially rendering the vehicle inoperable". Ram's 2025 2500/3500 manual for the Cummins is blunter: federal law requires Ultra Low Sulfur Highway Diesel, 15 ppm maximum.

Neither manual mentions dye. The color is not the problem; the sulfur can be. Most dyed diesel sold for off-road equipment today is the same 15 ppm fuel as the pump next to it, with dye added. But heating oil is dyed too, and it is not held to that limit. A red fuel of unknown origin, from a farm tank or a bulk supplier, may be fine or may be exactly the 500 ppm fuel both manuals warn about. The DPF and SCR system on a modern diesel are the parts that pay for it.

Our viewIf you can buy red diesel at a station pump labeled ultra-low sulfur, 15 ppm, it is the fuel your manual asks for, and the federal penalty is off until December 31. Check your state's rules first, and keep the receipt. If it comes from a farm tank or anyone who cannot tell you the sulfur content, skip it: a few cents a gallon is not worth an aftertreatment repair on a 6.7L Power Stroke, 6.7L Cummins or Duramax.

Sources

  • The White House, Executive Order "Emergency Tax Relief on Diesel Fuel", 5 Oct 2026 (published in the Federal Register 9 Oct 2026)
  • U.S. Energy Information Administration, Gasoline and Diesel Fuel Update, 6 Oct 2026 (U.S. on-highway diesel, week of 5 Oct)
  • 2025 Ford Super Duty Owner's Manual, p. 209 (diesel fuel requirements)
  • 2025 Ram 2500/3500 Owner's Manual, p. 382 (diesel fuel requirements)