President Trump issued an executive order this week aimed at making red-dyed diesel more accessible through the end of the year, as diesel prices remain high.

Red-dyed diesel is nearly identical to regular diesel, but is normally restricted to off-road use, mainly in farm and construction equipment. It is exempt from the federal fuel tax. The order aims to reduce costs for frequent diesel users, though how much they might save is unclear.

The U.S. average diesel price hit a record $6.52 a gallon a few weeks ago. It has since eased, but remains about $2.60 a gallon above its level a year earlier, according to AAA. Fewer crude shipments through the Strait of Hormuz, refinery outages in Russia and reduced diesel exports from Russia and China have tightened supplies.