Montana Department of Transportation

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Fuel Taxes

Dyed Diesel Use

What is Dyed Diesel?

Dyed diesel fuel is regular diesel fuel that has red dye added to it. This is done to identify the fuel as non-taxed and to help enforcement officials easily identify it. Dyed diesel is for off-road use only. Examples include farm equipment and home heating.

Dyed Diesel is for Off-road Use Only

dyed fuel animation

When you fill your vehicle with undyed fuel at the pump, state and federal taxes are included in the cost. These taxes are used to help fund construction and maintenance of Montana's public roads.

Dyed diesel fuel is fuel that has not been taxed and is intended for off-road use only.

Using untaxed fuel (dyed diesel) in a licensed vehicle violates Montana's law and reduces the money available to build and maintain Montana state highways.

Penalties for Misuse

If you fill your tank with dyed diesel and drive on Montana's public roads, you're breaking the law. The penalties for using dyed fuel on public roads in Montana are:

1st Offense
Up to $1,000.00 - Civil Penalty
2nd Offense
Up to $5,000.00 - Civil Penalty
3rd and Subsequent Offense
Criminal Penalty - minimum fine $535.00 - maximum $1,000.00 or by imprisonment for not less than 30 days or more than 6 months, or both.

Montana law requires the use of dyed diesel decals on retail pumps containing dyed diesel fuel, and this law is enforced.

Report Violators

The Montana Department of Transportation has cracked down on dyed fuel misuse. You can help. To report suspected violators, call MDT's 24-hour toll free tip line at: 1-888-FUEL-LAW or email Report Violators