HUNDREDS of hapless motorists are being hit with huge repair bills after mistakenly putting the wrong type of fuel into their cars.
Up to 100 people a month are calling the AA seeking help, with a number asking for assistance up to five times in the last year.
And the motoring group has urged anyone who has made the mistake not to turn their engine on, as it can cause irreparable damage to the car.
This is because petrol in diesel cars acts as a solvent and can reduce lubrication and cause damage to the fuel pump. In extreme cases, it can result in bills of up to €2,000 and sometimes the engine has to be replaced.
The problem is less serious when diesel is pumped into a petrol engine. If less than five litres is used, the rest of the tank should be filled with petrol and the car will run as usual.
The AA's annual breakdown review says there has been a 24pc increase in the number of mis-fuelling incidents, and it's far more common to put petrol in a diesel engine than the other way around. This is because the standard diesel nozzle is larger than the fuel filler neck on modern petrol cars.
"Most often it's drivers who have switched from a petrol to a diesel car who mis-fuel. Recently we even had one motorist mis-fuel twice in the one week; we also have customers who have called us out on four and even five occasions," AA spokesman Conor Faughnan said.
Drivers are often quite embarrassed, with some even opting to pay in cash so that their other half doesn't find out.
"Every time someone calls they feel as if they are the only idiot who could possibly make this mistake," technician Stephen Kavanagh added.
"In fact, we will deal with about a hundred calls a month. We had a case where a husband and wife both called us separately as both had made the same mistake and were anxious not to let the other one find out. We also had customers go to put the wrong nozzle in again immediately after we've drained their tanks they've been so flustered."
Other common problems include locking keys inside vehicles, which happens to one AA member per hour, while once a fortnight the AA is called after a young child or dog is locked inside with the keys.
The annual breakdown review reveals that flat batteries and punctures as ever remain the most common cause of breakdowns on Irish roads.
There are also subtle differences in the types of calls being received, which coincide with the older profile of vehicles on Irish roads. The percentage of breakdowns relating to steering, suspension and brake issues, for example, grew slightly this year in tandem with the age profile of vehicles on our roads.
According to the 2011 Irish Bulletin of Vehicle and Driver Statistics, 79pc of private cars in Ireland were four years and older while 60pc were six years and older. These figures compare to 71pc and 53pc in 2009.