What Is Red Diesel Fuel? Legal Uses, FAQs, and More

Did you know that diesel fuel comes in different colors? These colors all have specific and legal uses. Red diesel, in particular, is strictly used for certain vehicles and must not be used for road vehicles. It’s also one of the hardest types of diesel to procure.

What Is Red Diesel Fuel and How Is It Different?

Red diesel fuel is practically the same fluid as the regular diesel used in trucks and other daily drivers. The only difference is that red dye is mixed into the fuel to distinguish that it must be used exclusively for off-road vehicles and commercial purposes such as agriculture, construction, mining, and manufacturing. Red diesel may also be used for residential heating.

Commercial Uses

Carnivals, county fairs, and traveling road shows can use it instead of low-tax fuel. Construction companies use it for bulldozers, backhoes, cranes, and other equipment. Meanwhile, farmers utilize red diesel fuel in their tractors, harvesters, and other heavy equipment.

Residential Applications

Red diesel fuel is also used in non-commercial heating, but industries can’t use it to heat oil or generate power in commercial settings.

Why Is Red Diesel Fuel Illegal to Use in Some Vehicles?

Red fuel diesel and other dyed diesel types are illegal for use on road vehicles because they are tax-exempt and therefore heavily regulated. They are dyed so officials and testing kits can detect if a driver is illegally using them. Government investigators will test fuel at checkpoints, weigh stations, agricultural shows, etc.

There are a few exceptions when you may use red diesel on road vehicles. These include when the government declares a state of emergency or if the fuel supply is disrupted by a natural disaster.

What Is the Penalty for Using Red Diesel Fuel?

The fine for illegally using red diesel varies. You can get fined between $100 to $1,000 per gallon or get jail time. Distributors can’t sell to those planning to use red diesel illegally. You also can’t claim the associated tax exemptions if red diesel isn’t reported when used.

Other Diesel Fuel Colors

Besides red, you may also encounter diesel dyed in green, blue, or yellow. These diesels are colored differently for the following purposes:

• Identification of fuel
• Visual quality control
• Identification of a batch of fuel during storage at oil storage
• Continuous control

As for the colors themselves, they have different uses and characteristics:

Green Diesel

Green diesel is ecologically friendly and is also called renewable diesel or hydrotreated vegetable oil. Unlike red diesel, green diesel isn’t dyed and has a similar structure as petroleum diesel.

Blue Diesel

Blue diesel is similar to red diesel. The difference is blue diesel is not allowed for public purchase and can only be used by the government. However, even the government can’t use it on the road.

Yellow Diesel

Lastly, yellow diesel is specifically used for heating oil. The color helps distinguish it from motor oil. Some also say yellow diesel is cleaner due to lower sulfur levels.

FAQs About Red Diesel

Here are some of the frequently asked questions about red diesel.

Can I Use Red Diesel Fuel?

You can only use red diesel fuel in off-road vehicles for farming or construction. It’s illegal to use it in on-road vehicles.

Where Can I Buy Red Diesel Fuel?

You’ll need to find a specialist supplier to buy red diesel. They’ll look for a business fuel card to ensure you’ll use it for approved off-road equipment.

What Does Red Diesel Do to an Engine?

The only difference between red and regular diesel is the color, so using red diesel in your daily driver won’t affect the engine’s performance. However, the engine’s pipelines may get colored red due to the dye.

How Long Does Red Diesel Last?

Red diesel can last up to a year in a tank. It also has a similar shelf life if you have good storage and maintenance.

Can You Mix Red Diesel With Regular Diesel?

It’s technically possible to mix regular diesel with red diesel for the sake of mixing it. However, this will result in a mixture with a lower cetane rating than normal diesel. It could also cause problems with the fuel system, as the red dye may clog filters and injectors, reducing fuel flow and engine performance.

If you accidentally mix the two, the first thing to do is to stop using the mixture and drain the fuel tank. You may also have to replace filters and injectors to prevent damage to the fuel system.