Red Diesel Explained: Why You Cant Put it in Your Car

The Temptation of the Red Pump

If you live in a rural or agricultural area of the UK, you may have seen a separate, dusty pump at the petrol station offering "Red Diesel" (Gas Oil) at a price that is dramatically cheaper than the standard diesel pumps. With fuel prices squeezing budgets, the temptation to sneak the red nozzle into a standard road car is high. But doing so is a terrible idea.

What is Red Diesel?

Chemically, red diesel is almost identical to standard "white" diesel (B7). The only difference is that it has been dyed with a highly potent red chemical marker.

Red diesel is strictly reserved for off-road agricultural vehicles, tractors, construction machinery, and backup generators. Because these vehicles do not use public roads, the government applies a heavily discounted rate of Fuel Duty to red diesel. The massive price difference is entirely due to tax exemptions, not the quality of the fuel.

The Legal Consequences

Using red diesel in a vehicle driven on public roads is tax evasion. HMRC (Her Majesty's Revenue and Customs) takes this incredibly seriously. They deploy specialized road units with dip-testing kits to randomly check the tanks of diesel cars and vans.

If you are caught with red diesel in your tank, your car can be seized on the spot, crushed, and you can face an unlimited fine and a criminal record.

The Stain of Guilt

Even if you only put red diesel in your car once and then fill it with standard white diesel for a year, the chemical dye is so potent that it permanently stains the plastic inside your fuel tank and fuel lines. HMRC testers can detect the chemical residue months later. Do not risk it. Instead of risking your car being crushed, simply use FindPetrol to track down the cheapest legal, standard white diesel in your area.

Local prices differ far more than most drivers expect. For a worked example, see current petrol prices in Manchester.

Checking diesel prices near you

Whatever you drive, the price you pay depends far more on which forecourt you use than on anything else. Diesel currently starts at 144.9p a litre across the 7,916 stations we track, against a UK average of 182.6p - a spread worth several pounds on a full tank. Search your postcode to see diesel prices near me ranked cheapest first, or browse fuel prices by area to see how your town compares.