Petrol/diesel mix ups becoming more common
More and more owners are putting the wrong fuel in their cars as the prevalence of diesel increases.
Last year around 120,000 UK drivers suffered the embarrassment of calling out a breakdown service after filling up their cars with the wrong type of fuel.
The cost of draining the bad fuel and then the repairs - especially for cars with catalytic converters - can be anything from a few hundred to many thousands of pounds.
In fact it is happening on average around 400 times a day in Britain, with each mistake costing up to £6,500 to fix.
Breakdown service Autonational Rescue reckon that it's too easy to do.
"It's so easily done. If you're running around in someone else's car or a fleet car from work then the likelihood of your making a mistake at the pumps increases significantly," says Autonational's marketing manager Ronan Hart.
Diesel pumps at petrol stations are often unhelpfully positioned right next to the petrol pumps, or simply coloured slightly differently, so drivers can easily be mislead on the filling station forecourt.
There are however some products on the market which help to prevent misfuelling, the cheapest of which attaches to the inside of your fuel flap.
They can also remind you that your car runs on diesel with an audible warning, so that even if you are running on "auto pilot" yourself, you will be unlikely to fill up with the wrong fuel.
So what happens when you put the wrong fuel in your car?
Petrol wrecks a diesel engine lubrication process, and is particularly damaging to its costly, high-pressure pump, fuel injection system and filters.
So if you know you've made the classic mistake, don't start the engine just seek professional advice straight away.
If you have already started the engine and driven off, then you may get half a mile or so down the road before your car gives up the ghost on you.
The next step would be to call your breakdown service, or a local garage if you don't belong to one.
They won't drain the fuel on the spot but can arrange to take the car to your dealer, and if you are especially lucky, they will be able to drain the tank and clean the hoses, purge the fuel from pumps and replace the filter.
If you are not so lucky, the job will be considerably bigger (in the case of executive cars it can mean a replacement engine at a cost of up to £12,000) and then it's a case of contacting your insurance company, fingers crossed, to see if you are covered.
In principle that kind of accidental damage can be covered by comprehensive insurance, says the Association of British Insurance, but it is well worth checking your own policy as very often they are specifically excluded from motor policies, especially third party-only.