Whether you’ve put petrol in diesel or diesel in petrol, the best thing to do is avoid starting the car if you haven’t already. However, don’t panic if you have - acting quickly and calling a mobile roadside fuel drain service could minimise any damage and get you back on the road quickly. If you’re stuck on a petrol station forecourt, tell the staff you’ve made a mistake, as the chances are they’ll be familiar with the situation and might even offer you a push to a suitable spot where you can wait for assistance.
Diesel fuel pumps need more lubrication than petrol, and putting petrol in to a diesel vehicle reduces this. It will cause the fuel pump to run without lubrication, causing the metal parts to rub together, which can quickly cause damage and will likely see you stutter to a stop if you try to drive away.
It’s less common for diesel to be put in petrol due to the size of the nozzle, but if you do be sure to seek expert assistance.
The answer to this question will, of course, vary, depending on the damage caused to the engine. A mobile roadside fuel drain can cost as little as £175 to £300 with some firms (although costs vary). However, recovery to a local dealer is likely to set you back closer to £400, with the added downside that the fuel has spent longer in the vehicle. In some cases more serious work may need to be carried out, which could see costs run in to the £1,000s.
Starting the engine turning on the ignition will cause the contaminated fuel to circulate, increasing the likelihood of serious damage to the engine. In any case, a petrol vehicle is unlikely to run for more than a very short spell, while a diesel with the wrong fuel in it is unlikely to manage more than a few miles.
It’s estimated that at least 150,000 drivers put the wrong fuel in their car each year . That’s equivalent to an incident every three-and-a-half minutes.
To show just how easy a mistake it can be to make, we asked a few people who’d put the wrong fuel in their car to share their experiences with us:
"I’d passed my driving test, and couldn’t wait to go and visit family to show off my new car. Being cautious, I stopped to fill my tank when it hit the halfway mark. The last thing I wanted to do was breakdown! Following all of the instructions my dad had passed on about wearing the plastic gloves and ensuring my car engine was turned off, I felt confident about filling up.
Half way through, I froze when I realised I’d put petrol in my diesel car. Not knowing the possible implications, I thought everything would be fine. It was still fuel right?! How wrong I was! Just when I thought I’d gained my independence, dad, and the car breakdown service had to come and save the day!"
"Never fill up your car after a day of driving across Wales! Being over tired, and not being used to the language difference, I filled my petrol car with diesel. It’s an expensive mistake I will never make again. Luckily, I was still at the garage when I realised. I called the Fuel Doctor, and they were able to drain the tank, and resolve any potential damage."
"I’d hired a VW campervan with my wife, as we wanted to go to Cornwall for the weekend to get away from the city and stresses of work. Feeling relaxed, and in the holiday spirit, it seems I’d left my mind in the office! Leisurely I filled the tank, drove a mile down the coast, when my other half asked how much the petrol had cost. I’d just filled the tank with diesel! Let’s just say we could have taken a trip to Europe for the cost of fixing it."
"Living in the countryside means that petrol stations are few and far between. Christmas was the first time I’d been home, after six months of living abroad to pursue my new dream job. No sooner had I walked through the front door, I was sent on my way in mums 4x4, to collect the turkey from the butchers in the next village.
Being the dutiful daughter, I decided to fill the tank as an early Christmas present. Two hours, one tow truck bill, and a broken car later, I returned home to discover that petrol does not belong in a diesel tank. I think I’ll leave filling up to another family member next year!"
Disclaimer - All information included in this Swinton Insurance guide was carefully sourced from external sources in March 2015. We’ve made every effort to make sure the information we’ve included is completely accurate, but please keep in mind this is only a guide, and should be treated as such.