Off-road diesel is the same as regular diesel except for its color, cost, and permitted uses. On-road diesel fuel includes taxes to cover the creation and maintenance of roads. Since off-road diesel is supposed to be used for off-road purposes, it is exempt from these taxes.
Off-road fuel is primarily used in the construction and agricultural industries. Equipment like tractors, dump trucks, and generators tend to have diesel engines. Off-road diesel offers a cheaper way for farmers and construction companies to fuel their machines.
Technically, off-road diesel can be used in any engine operating off-road. So if you want to fill your 4x4 rig with it, you’re welcome to. The only issue is you can’t legally drive on any roads to get to or from the off-roading location.
WHAT COLOR IS OFF-ROAD DIESEL?
One of the ways to track off-road diesel is by its color. In the U.S, off-road diesel is usually dyed red. Government vehicles can use blue dye diesel as well. Without this dye, there would be no easy way for law enforcement to check for taxed/untaxed fuel.
IS RED DIESEL FUEL ILLEGAL?
If a police officer catches you driving with red diesel on a public road, you could face serious charges. Because off-road diesel is untaxed, if you’re caught using it on public roads, you can be charged with tax evasion. That’s a felony that can carry a sentence of up to five years in federal prison. At the very least, you’ll be looking at stiff fines.
Even though the fuel in your tank isn’t visible to the world, it’s easy to check. Law enforcement officers can detect dyed diesel by dipping a clear tube into your vehicle’s fuel tank. If the color is red or blue, you’re in trouble.
Attempting to remove dye from untaxed diesel is also illegal. While it’s possible to make the fuel look undyed and clear, there are chemical traces left in the fuel that are easy to spot in a lab.
CAN RED DIESEL DAMAGE YOUR ENGINE?
Dyed diesel won’t harm your engine or produce less power. It should have no more impact on performance than regular diesel would.
What About High Sulfur Fuel?
The sulfur content of diesel is another concern when it comes to engine performance. Any off-road diesel produced after 2014 must meet EPA standards for ultra-low-sulfur diesel (15 ppm). So if you’re purchasing fresh off-road diesel, you’ve got nothing to worry about.
Off-road diesel made before 2014 might have higher sulfur content though. If your diesel fuel is older, you should avoid using it in car engines from 2007 onwards. Since on-road diesel transitioned to ULSD in 2006, high sulfur diesel could damage emission controls and the engine.
WHAT DOES OFF-ROAD DIESEL COST?
Red dyed diesel costs depend on the same factors that influence the price of all fuel (such as location and scarcity). Since the price of off-road diesel is just the standard diesel price minus state and federal fuel taxes, you could save anywhere from 30 to 80 cents per gallon. Not enormous savings, but enough to make a difference.
WHERE CAN YOU GET OFF-ROAD DIESEL?
Off-road diesel fuel can be bought the same way any other fuel can. While not as common as gasoline or road-legal diesel, there are gas stations that sell off-road diesel from a separate pump. If you’re looking for a place to buy red dye diesel, then the CFN pump locator will point you in the right direction. Enter your address to find the nearest off-road diesel pump.
SHOULD YOU USE RED DIESEL?
Off-road diesel is a great option if you plan on using it as intended. As long as the fuel isn’t in your engine while on public roads, it’s completely legal to carry off-road diesel with you in separate containers like jerry cans. You can calculate how much regular diesel fuel you’ll need to make it to the trail and refill with your off-road diesel when you get there. Some drivers may find that the risk and added effort aren’t worth the savings though.
This article was researched, written, edited, and reviewed following the steps outlined in our editorial process. Learn more about CJ's editorial standards and guidelines.