What is red dye diesel

On 2 October 2026, the Internal Revenue Service issued a formal reminder regarding the legal restrictions surrounding the use of red-dyed diesel fuel. Red-dyed diesel is chemically identical to standard ultra-low sulfur diesel used in highway vehicles, but it contains a red dye additive to signify that it is exempt from federal and state excise taxes. This fuel is strictly intended for off-road purposes, such as agricultural equipment, construction machinery, home heating systems, and stationary generators. The agency emphasized that using red-dyed diesel in vehicles operated on public roads remains a significant violation of tax law. Because the fuel has not been taxed for highway use, its presence in a road-legal vehicle’s fuel system can lead to substantial financial penalties and fines for operators. The IRS noted that enforcement efforts have increased in recent months to ensure compliance, as the tax revenue from highway diesel is essential for the maintenance of public infrastructure. Operators are advised to maintain clear records of fuel purchases to distinguish between taxed and tax-exempt supplies.