What Happens If You Put Off-Road Diesel in a Truck? Understanding the Differences Between On-Road and Off-Road Diesel

Diesel fuel is a common choice for powering trucks and other heavy-duty vehicles. However, not all diesel fuels are created equal. There are distinct differences between on-road and off-road diesel, and using the wrong type can have serious consequences. This article will delve into these differences and explain what happens if you put off-road diesel in a truck.


On-Road vs. Off-Road Diesel: The Basics

On-road diesel, as the name suggests, is designed for vehicles that operate on public roads. This is the type of diesel you’ll typically find at gas stations. Any vehicle licensed for use on roads in the United States is required to use on-road diesel.

On the other hand, off-road diesel is intended for machines not driven on public roads, such as tractors, construction equipment, and generators. Using off-road diesel in a vehicle that drives on public roads is not legal. Doing so can result in significant fines.

The Color Difference

One of the most noticeable differences between on-road and off-road diesel is their color. On-road diesel is often called “clear diesel” because it’s transparent. Off-road diesel, conversely, is known as “dyed diesel” or “red diesel” because it’s typically dyed red. This dye serves as a visual indicator to prevent mix-ups and allows for easy testing to determine the type of diesel in a vehicle.

The Tax Difference

Another significant difference between on-road and off-road diesel lies in taxation. Because off-road diesel is not used on public roads, it’s not subject to the same taxes as on-road diesel, making it cheaper. On-road diesel, however, is subject to an excise tax because it’s used on public roadways.

In terms of performance, there’s no difference between the two types of diesel. However, using off-road diesel is less expensive for businesses operating off-road vehicles because it avoids unnecessary state and federal taxes.

What Happens If You Put Off-Road Diesel in a Truck?

If you put off-road diesel in a truck that’s driven on public roads, you’re breaking the law. The red dye in off-road diesel is detectable in inspections, and if found in an on-road vehicle, it can result in hefty fines. The fines are designed to deter tax evasion, as using off-road diesel in an on-road vehicle avoids the taxes associated with on-road diesel.


Understanding the differences between on-road and off-road diesel is crucial for anyone operating diesel-powered vehicles or equipment. Using the wrong type of diesel can lead to legal issues and hefty fines. Always ensure you’re using the correct type of diesel for your vehicle to avoid any potential issues. Trust My Auto Machine for all your automotive information needs.

About the author, Laurence Perkins

Laurence Perkins is the passionate car enthusiast behind the blog My Auto Machine. With over a decade of experience in the automotive industry, Perkins has knowledge and experience with a wide range of car makes and models. His particular interests lie in performance and modification, and his blog covers these topics in-depth. In addition to his own blog, Perkins is a respected voice in the automotive community and writes for various automotive publications. His insights and opinions on cars are highly sought-after.