Wrong fuel on a motorway: stop safely, use hazard lights, don't restart
Put the wrong fuel in on a motorway? Stop safely, switch on hazard lights, and don't restart the engine. Here's what to do next.
Wrong fuel on a motorway: stay calm and stay safe
Putting the wrong fuel in your vehicle is a stressful moment at the best of times — and it can feel even more unsettling when it happens on a busy motorway. The most important thing to remember is that your safety comes first. The fuel mistake itself is manageable, but only if you handle the situation calmly and correctly from the very first moment.
Stop safely and switch on your hazard lights
If you realise you have misfuelled while still at the forecourt, do not start the engine. If you have already pulled away and notice something is wrong, ease off the accelerator, signal, and move carefully to the hard shoulder or the nearest safe stopping point. Switch on your hazard lights immediately so other drivers can see you, and keep them on until help arrives.
Once stopped, turn the engine off and do not attempt to restart it. Restarting the engine circulates the wrong fuel through the fuel system, which can cause substantial damage to components such as the fuel pump and injectors. The less the wrong fuel is moved through the system, the better the outcome for your vehicle.
Why you should never restart the engine
Petrol in a diesel vehicle reduces lubrication and can quickly damage high-pressure fuel system parts. Diesel in a petrol vehicle can cause misfiring, heavy smoke, and poor running. In both cases, turning the key again simply pushes the contaminated fuel further through the system. Leaving the engine off is the single most effective step you can take to limit the extent of any repair work.
What to do now
Move yourself and any passengers to a safe place away from traffic, ideally behind a barrier. Do not stand near the vehicle or on the carriageway. Once you are safe, call for help. EEK Mechanical arranges for a tow truck to collect your vehicle from your location — whether that is a forecourt, the hard shoulder, or a nearby safe area — and transport it to a GBIFDA-certified workshop.
Manufacturer-spec fuel system recovery is completed only at the workshop, never at the collection location. This means your vehicle is handled properly, with the correct equipment and procedures, rather than being worked on at the roadside where safety and precision are harder to guarantee.
Get your vehicle recovered safely
If you have put the wrong fuel in your vehicle, call the EEK Mechanical customer hotline on 0808 280 6346. Our team can arrange vehicle collection and workshop recovery, with fully itemised pricing available on our rate card. Costs vary depending on tow distance, after-hours timing, and your vehicle, so the team will talk you through exactly what is involved before anything proceeds.
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