Key statistics. Approximately 150,000 drivers in the UK misfuel their vehicles each year. (Allianz Insurance, Admiral, Wrong Fuel Recovery, 2025-2026). Nearly 30% of UK motorists have accidentally used the wrong type of fuel when filling up their vehicle. (Go.Compare, 2025).
When you accidentally put the wrong fuel in your car or encounter contaminated fuel, the immediate priority is to avoid starting the engine and to seek professional help as quickly as possible. Ignoring the issue can lead to significant and costly damage to your vehicle's fuel system and engine components, requiring extensive repairs.
What exactly is misfuelling and why is it so common?
Misfuelling occurs when you put a different type of fuel into your vehicle than it's designed for, most commonly petrol into a diesel car or vice versa. This mistake is surprisingly frequent, with approximately 150,000 drivers in the UK misfuelling their vehicles each year, and nearly 30% of UK motorists admitting to accidentally using the wrong fuel at some point. In the US, around 90,000 misfuelling incidents occur annually. These numbers highlight just how easy it is to make this costly error, often due to distractions, rushing, or driving an unfamiliar vehicle.
Region
Annual Misfuelling Incidents
Frequently Asked Questions
What should I do immediately if I put the wrong fuel in my car?
The most important step is to NOT start the engine. Do not even turn the ignition key. Inform staff if at a fuel station, put the car in neutral, and call for professional assistance to drain the fuel.
What are the common signs of contaminated fuel or misfuelling?
Signs include the engine running rough, difficulty starting, loss of power, unusual noises, excessive smoke from the exhaust, or the illumination of dashboard warning lights.
How much does it cost to fix misfuelling?
A basic fuel drain and flush can cost approximately £130-£400 in the UK or $200-$500 in the US if the engine hasn't been started. However, if the engine has been run, leading to damage to fuel system components, repairs can range from £1,500-£5,000+ or $4,000-$17,000+.
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Sofia MarshResearch & Fact-Check Lead
Sofia Marsh researches and fact-checks every Carvy guide against official vehicle authority and manufacturer data before publication, so drivers get clear, accurate answers they can rely on.
