President Donald Trump is set to sign an executive order on Oct. 6 aimed at lowering diesel prices by expanding access to tax-exempt dyed diesel. The measure could increase supplies of red-dyed fuel used by agriculture and some off-road vehicles, direct the US Department of Transportation to coordinate with states on waiving road-diesel taxes and include a US Treasury Department review of diesel-related taxes. Diesel prices reached a record of about $6.50 a gallon last month, while the average US price is $6.32, down 13 cents from a week earlier but $2.63 above a year earlier. Fuel prices have risen amid wars in Iran and Ukraine and attacks on refineries in Russia and the Middle East. G7 countries have announced plans to release 100 million barrels of diesel, although the amount representing new supply remains unclear. Trump has ruled out an export ban, while some Republicans oppose tax waivers because states use fuel-tax revenue for infrastructure.