There was a time when diesel fuel was sold in the U.S. without dye added to it, but times have changed.
The U.S. government now requires diesel gas to be sold within three different varieties: clear, red, and blue. Understanding the difference among these fuels – and among the tax and legal implications of each – is critical if you intend to purchase diesel fuel.
Here are some basics about the three types of diesel fuel:
- Clear diesel – Clear diesel is a road vehicle-grade fuel that is available for sale at gas stations throughout the U.S. This type of fuel is meant for use by the vehicles that travel the roads every day – cars, trucks, SUVs, etc. – along with marine vehicles. When most people think of diesel fuel, this is the fuel they think of.
Clear fuel has low sulfur levels and is legally taxable. Any vehicle that has a diesel engine and is licensed by the state for on-road use must use this fuel.
- Red-Dyed diesel – Most dyed diesel sold in the U.S. is colored red (with the chemical additive Solvent Red 26 or 164). By law, red-dyed gas is only for use in off-road vehicles, including farm tractors, heavy construction equipment, and generators, where higher sulfur fuel use is permissible.
Because it is not to be used for on-road vehicles, this fuel is not taxed within the United States.
- Blue-Dyed diesel – Blue-dyed diesel is identical to Red-dyed diesel, except that it is used only for U.S. Government vehicles. Blue-dyed diesel is not available to the general public.
Regulations on dyed diesel
Because dyed diesel is not taxed, federal and state laws strictly regulate its use; penalties for improper use of dyed fuel range from stiff financial penalties to significant jail time. Distributors cannot knowingly transport dyed fuel with the intent to supply on-road vehicles, and fuel retail locations that carry dyed diesel cannot knowingly sell the gas for use in an on-road vehicle. If you are a retail diesel customer, you cannot knowingly use dyed diesel in an on-road vehicle; if dye is found in an on-road vehicle, the penalties can be extremely high. Be smart!