What is Red Diesel? Ultimate Guide

What is Red Diesel? Read this ultimate guide to find everything you need to know. We will explore what this alternative fuel is, why it’s illegal to use on the roads, who can use it and how it is made. We will also answer some frequently asked questions.

What is Red Diesel?

Red Diesel
Image Credit: Pixabay

Red diesel is a type of fuel that is used in a variety of vehicles and machines. It is often used for agricultural purposes, as well as construction and other industrial work. However, it is illegal to use on the roads in the UK.

The Diesel era has been a major player in the auto industry for decades. With its low price and availability at every corner, it quickly took over as more people bought diesel-powered cars which led to restrictions on how much can be used.

The government started restricting the use of this type of diesel in the early 2000s. The government made it illegal to use it on public roads. This was mainly because it contains a higher amount of sulphur than regular diesel, which can damage the environment.

With fuel becoming more expensive year after year, more and more people are looking for ways to cut costs. This has led to an increase in the use of red diesel, as it is significantly cheaper than regular diesel. Red diesel is often used by farmers and other agricultural workers, as well as construction workers and those in the industrial sector.

What is it made of?

In the process of being refined, red diesel is made from crude oil just like other petroleum products. The decay and removal of animal matter, as well as vegetable geology, occurs at the surface level before it enters large distillation towers which cause heat to separate components by their boiling point characteristics; this includes both liquids (such as gasoline) that boil under applied pressure or gases relying on their natural force alone – without any assistance whatsoever!

The lightest of all these components will rise to the topmost part while the heaviest settle at the bottom; this is how crude oil is transformed into gasoline, kerosene, and finally diesel. However, there are still some hydrocarbons left over that don’t quite make it into any of those categories. These “leftovers” are what we call gas oil, and red diesel is made from this gas oil.

The refining process of red diesel is ultimately not much harder than that for clear fuel. The main difference lies in how it’s marked before being sent out into the market, but once again only one step needs special attention- adding this dye at later stages when everything else has already been prepared.

The dye gives red diesel its name and colour, but it also serves another purpose. The dye is used to help customs officials identify if the fuel is being used for its intended purpose.

Diesel Rig
Image Credit: Pixabay

Why Is it Illegal?

There are two reasons why public use is illegal. One of the main reasons is that it does not meet the environmental standards that are required for road use.

High Amounts of Sulphur

The main difference between red diesel and regular diesel is the sulphur content. Red diesel has a higher sulphur content than regular diesel. This sulphur can cause environmental problems when it is burned. Sulphur dioxide is one of the main pollutants emitted by vehicles that use red diesel.

Sulphur dioxide can cause acid rain, which can damage crops, trees, and buildings. Sulphur dioxide can also cause respiratory problems in people.

The government has set environmental standards for the sulphur content of diesel fuel. Red diesel does not meet these standards.

Lower Amounts of Tax

Another reason that red diesel is illegal is that it has a lower amount of tax than regular diesel. The government taxes diesel fuel to help pay for the maintenance of roads and bridges. Red diesel does not have the same amount of tax as regular diesel, so it is illegal to use on the roads.

Who Can Use Red Diesel?

This commercial fuel source can be used by farmers, construction workers, and other industrial workers. It can also be used in certain types of vehicles, such as agricultural machinery, boats, and generators.

The reason only farmers, construction workers, and other industrial workers are legally allowed to use red diesel is that their vehicles are not used on the roads.

Construction workers are big fans of red diesel because it is cheaper than regular diesel. This means that they can save money on their fuel costs. Construction equipment can take up a lot of fuel, so even small savings can add up.

What Vehicles Can Use Red Diesel?

Boat using Red Diesel
Image Credit: Pixabay


Tractors are permitted to use this fuel source because they are not used on the roads. Tractors are only used on farms, so they will not be evading road tax.

Site Machinery

Site machinery is allowed to use this type of diesel because they are only used on construction sites. Site machinery generally doesn’t go on the roads.


You may use red diesel in a generator because they are used on site. Generators are only used to produce electricity.


Boats are permitted to use this fuel because they operate solely in a marine environment. ie. rivers and lakes. They will not be breaking any road tax laws or contributing to the pollution problem on the roads.

Any machine that is commercially used and not for domestic use can run on red diesel. This is to say that if the machine in question will never be used on public roads, then it’s probably eligible to use red diesel.

How Would I Get Caught Using Red Diesel?

UK Police
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In the UK, HMRC has to power to inspect any vehicle and open its fuel tank for examination. The vehicle will be seized and a release fee will be payable. HMRC frequently inspect the paperwork of businesses selling this commercial fuel source.

If you are caught using it on the roads, you will be fined. The amount of the fine will depend on the severity of the offence.

A lot of people who work on building sites use red diesel to fill their vans up. This is because it is much cheaper than regular diesel. Red diesel can stain the ground and any equipment that it comes into contact with, which can make detection easier for the authorities.

What is the fine for using Red Diesel?

Using red diesel illegally is essentially tax evasion, a lower rate of duty has been dishonestly paid.

There is no fixed amount if caught misusing, however, fines up to £250 per offence are common. You will additionally be charged for the removal and disposal of the fuel. Repeat offenders and serious instances have been known to reach multiple thousands. The HMRC website states serious offenders can be fined an unlimited amount and face a prison sentence of up to 7 years, or both.

What Are Red Diesel Licences

You don’t need a licence to purchase this type of fuel, but you must sign an RDCO form upon buying it. You can only buy gas oil from companies that are registered with HMRC and have the appropriate taxation paperwork for them not to be subject to high taxes when selling their products at auction or marketplace price floors which may result due to unregistered sellers who sell below cost-of-goods.

Where Can I Buy Red Diesel?

You can buy it from a variety of places, including commercial fuel depots, farmers, and construction workers. However, it is important to remember that it is illegal to use on the roads.

Fuel Tanker
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Is Red Diesel Dangerous?

No, is not dangerous per se. It is simply a type of regular diesel dyed red so that it can be easily identified.

It is safe to use in the appropriate vehicles and for the appropriate purposes. However, it is important to remember that it is illegal to use red diesel on the roads.

It is flammable like any other oil-based product. But as long it’s used for its intended purposes, there is limited danger.


Red diesel is not completely exempt from tax, but it’s a heavily rebated fuel so the amount you pay in taxes isn’t as much. This is because the government wants to incentivize people to use red diesel for agricultural and construction purposes.

The lower tax helps construction companies run on cheaper fuel, which in turn helps to keep costs down for the consumer. It’s a way of the government subsidise an industry that is essential to infrastructure development.

Also, essential businesses like farming that provide important food resources for the country are given a break on fuel taxes to help keep their operations running smoothly.

Alternatives to Red Diesel

If you are caught using it on the roads, you will be fined. The amount of the fine will depend on the severity of the offence.

One alternative is biodiesel. Biodiesel is made from renewable resources, such as vegetable oil or animal fat. It can be used in any diesel engine, and it burns cleaner than regular diesel.

Another alternative is electric vehicles. Electric vehicles are becoming more and more popular, and they do not produce any emissions. With the rise of electric and now hydrogen-powered commercial vehicles, there might be a chance that red diesel will one day be phased out entirely. This would be significantly better for the environment and perhaps cheaper as renewable power becomes more readily available.

Tractor using Red Diesel
Image Credit: Unsplash


Does red diesel damage cars?

No, it will not damage your car. However, it is important to remember that it is illegal to use it on the roads.

How much does red diesel cost?

The price varies depending on the supplier. However, it is typically much cheaper than regular diesel.

Can red diesel freeze?

Diesel fuel gelling can occur when the temperature drops and contains wax paraffin which usually improves its lubrication properties. However, too much of it becomes cloudy due to thickening caused by cold weather conditions that could eventually clog filters or cause your engine not to work at all!

Can you remove the dye from red diesel?

This is a big no-no! The process to remove red dye from gas oil can lead you into trouble. Even though it’s technically illegal, there will still be traces of the pigment in your engine and if found doing this illegally then chances are that one could face a large fine or worse – not worth taking those risks for some extra cash right?

Is Red diesel more flammable?

No, is not more flammable than regular diesel. However, it is important to remember that all diesel can be dangerous from improper use.


Diesel pump
Image Credit: Unsplash

This is a type of fuel that is used in off-road vehicles and machinery. It’s also known as agricultural diesel, tractor diesel, or green diesel. Red diesel is dyed red so that it can be easily identified by authorities.

Red diesel is not the same as gasoline, which is the type of fuel that cars run on. Gasoline has a higher octane rating than red diesel and doesn’t produce nearly as much heat.

Red Diesel vs White Diesel: The biggest difference between red and white diesel is the colour dye that’s added to red diesel to help identify it. Other than that, they are both very similar fuels with the same properties. Its main use is powering agricultural machinery and other off-road vehicles. It’s also common to see this fuel being used in construction equipment and generators.

While it is not as widely available as regular diesel, it can be purchased from commercial depots, farmers, and construction sites. It’s important to remember that it is illegal to use on the roads. If you’re caught using red diesel on the roads, you will be fined.

We hope you have found this article informative and useful. Have you used this type of fuel before? Feel free to leave a comment below.


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