There is no chemical difference between on-road and off-road diesel fuels. On-road diesel, also known as clear diesel, can be purchased at the local gas station. Off-road diesel is dyed red and is sold through bulk distributors.
The only differences are in the color, cost, and intended use. In the past, off-road diesel had a higher sulfur content, which caused a smokier burn. With changes to fuel specifications from the Environmental Protection Agency (EPA) gradually implemented beginning in 2008 and completely enacted in 2014, the two fuels are chemically identical except for the coloration.
What Is Off-Road Diesel?
As the name implies, off-road diesel is for use by farms (agricultural use), industrial, and construction vehicles that do not travel on public roadways. It is not taxed, which allows a lower pricing scale. Using red-dyed diesel in the truck you drive to and from work could net you a hefty fine.
Nontaxed diesel fuel uses are defined in both state and federal tax laws. While the federal laws are applicable in all states and territories, some specific uses may be permitted within individual states. Tax rates also vary from state to state, although the federal taxes remain the same across the board.
The goal of increased regulations regarding off-road diesel is designed to reduce emissions control as part of the clean air initiative. By reducing sulfur content, off-road fuels are producing fewer air pollutants. In many instances, exhaust emissions have been decreased by as much as 90%.
Emissions standards for diesel-powered marine vessels and locomotives are not included in current regulations. There are plans to revise and apply a more strict policy regarding these uses in the near future.
What’s the Difference Between Off-Road Diesel and Regular Diesel?
As stated, other than the cost, color, and usage, there is no difference. Regular diesel fuel has been regulated more stringently by the EPA in the past. Since 2014, regulations for emissions standards, sulfur content, and fuel quality have been leveled across the board for both on-road and off-road diesel.
Simply stated, off-road diesel is not taxed and cannot be utilized in any vehicle or equipment that traverses public roadways. On-road diesel is fully taxed and available for consumer purchase at most fuel stations.
What Vehicles Require Off-Road Diesel?
Technically, no vehicle “requires” off-road diesel. Every vehicle that has a diesel engine can use on-road diesel fuel. However, that creates an extra tax burden on farmers, construction firms, and others who do work that does not use public roads.
Off-road diesel can be as much as 25 cents cheaper per gallon. This can mean significant savings for high-use industries such as construction and agriculture. However, improper use of off-road diesel can result in fines up to $10,000. Trying to avoid high commuter fuel costs will cost more than you save by evading the taxman.