President Donald Trump issued an executive order this week aimed at making red-dyed diesel more accessible through the end of the year, as diesel users face high fuel costs.

Red-dyed diesel is generally reserved for off-road equipment, including farm tractors and construction machinery. It is taxed differently from the diesel sold at most filling stations and is exempt from the federal fuel tax.

U.S. diesel prices reached a record average of $6.52 a gallon a few weeks ago. Prices have since eased, but a gallon still costs about $2.60 more than it did a year earlier, according to AAA. The order's effect on prices remains uncertain.