Company car drivers are among the culprits and fleet decision-makers will want to ensure drivers are adequately informed, especially those who use pool or hire vehicles on a regular basis.
A spokeswoman for breakdown specialist Green Flag said the most common cause of mis-fuelling was putting petrol in diesel cars. She said: ‘This can often happen when people are driving for business purposes in unfamiliar vehicles such as hire cars.’
Petrol being put into diesel cars is usually more common as the narrow petrol nozzle fits into the wider diesel tube. The problem is also increasing because of the surge in popularity of diesels in recent years.
Mike Waters, head of market analysis at fuel card supplier Arval, said: ‘The increase in the number of diesel vehicles has resulted in a dramatic increase in the number of absent-minded drivers putting the wrong fuel in their cars.
‘Typically, there is a high occurrence of ‘wrong fuel fill-ups’ in the first few months of new vehicle ownership when the change in fuel type temporarily slips the driver’s mind.’
In 2003, the AA was called to 43,000 vehicles which had broken down because the wrong fuel had been put into the tank and, according to the roadside assistance group, mis-fuelling wastes enough fuel to fill 150 petrol tankers every year.
It is not just fuel which is wasted. The cost of repairing a mis-fuelled vehicle can be thousands of pounds. Just two drivers mis-fuelling in a year could dent a fleet budget by more than £10,000.
The repair cost depends on whether the driver attempts to start the vehicle following the mis-fuelling.
If a driver puts petrol into a diesel vehicle and realises the mistake before turning on the ignition, the repairer will be able to drain the fuel and flush the system, usually at no more than a charge of £100.
However, if the driver starts the engine, it is likely that the injection components, fuel and filters will have to be replaced with a considerable increase in the repair cost.
Arval estimates that wrong-fuel fill-ups, in the most severe cases, can result in repair costs of between £3,000 and £7,000 per vehicle, depending on the marque.
Chris Hunt, director general of the UK Petroleum Industry Association (UKPIA), added: ‘Although the number of incorrect fuellings is a tiny proportion of the billions of fill-ups at filling stations each year, these mistakes represent a serious inconvenience and potential heavy cost for customers affected.’
It is not only the cost of repairing a mis-fuelled vehicle which can inconvenience fleets, but also the risk of rendering the vehicle warranty invalid.
Arval claims car manufacturers are clamping down on driver attempts to claim on the manufacturer’s vehicle warranty for ‘wrong-fuel fill-ups’ due to soaring number of claims.
Waters said: ‘Vehicle manufacturers are being increasingly vigilant about motorists trying to avoid responsibility for their mistake by claiming on the vehicle warranty.
‘Ultimately, this could mean higher costs for fleets should the warranty claim be rejected. Most vehicles carry a label on the fuel cap to remind the driver of fuel type, but we recommend another label is placed on the dashboard, particularly in the first few months of ownership.’
It is in the interests of fleet managers to make drivers aware of the consequences of mis-fuelling.
There are several ways to ensure the message gets across. Most filling stations have now standardised the colour of nozzles to prevent confusion, with some carrying messages alerting the issue to drivers. National campaigns have also begun to tackle the problem.
The AA Motoring Trust launched its ‘Use your Nozzle’ campaign last year. Cards carrying a warning were distributed to AA members through three million copies of its magazine and motorists were handed one of nine million advice cards at more than 5,000 UK fuel stations.
Fleets are also taking action. Hampshire Police fleet chief John Bradby developed a poster to remind drivers after a series of fueling errors.
There are also several gadgets on the market which aim to prevent drivers mis-fuelling. These include Easy-Cap, a replacement fuel filler cap that fits either on diesel or petrol vehicle caps and enables only the correct type of fuel nozzle to be inserted.
A product called Diesel Guard is also available which reminds drivers that the car runs on diesel fuel with an audible warning message each time the filler cap is opened.
‘I couldn’t believe I had been so stupid’ – driver
MIS-FUELLING can be a simple mistake to make if drivers are regularly using different vehicles such as pool or hire cars or even if they are distracted. One fleet driver made the costly mistake of putting unleaded petrol into her diesel fleet car. She explained: ‘I was in a hurry to get to the train station and was running late. I quickly nipped to the garage to fill up before going to the station and mistakenly put unleaded petrol into my diesel pool car.
‘I drove for about five miles, parked up, put my passenger on the train and when I tried to re-start the car I realised my mistake.
‘I was so embarrassed and couldn’t believe I’d been so stupid.’
Roadside assistance was called and the car was taken to a local garage which drained the engine.
The driver added: ‘Luckily the engine was not damaged, but it cost £177 to have it drained and tested.’
The AA Trust said it is worse to put petrol into a diesel engine rather than vice versa, so this driver was relatively lucky.
A spokesman from the Trust said: ‘The engineering in the latest diesel engines is so fine that there is little tolerance for allowing petrol into the system. The diesel provides lubrication for the high pressure diesel pump and by adding petrol, parts of the pump break up, causing the damage.’
What to do if a driver mis-fuels
FLEET managers should issue clear guidelines to drivers showing what to do if they accidently opt for the wrong fuel.
The AA Trust advises motorists if they have filled up with the wrong fuel they should not start the car.If necessary, push the car away from the pump, park it safely and call a breakdown organisation for help.
The Trust also recommends fleets to advise drivers to double check they are holding the right nozzle and read the pump label.
Make sure it is the right fuel for the car, checking the markings on the filler neck and never force a larger nozzle into a smaller filler neck as it means it is the wrong fuel. It seems obvious, but many drivers do not do it.