The big problem comes with the complexity of modern engines and at one recent SMR seminar one manufacturer revealed that this simple mistake could cost up to £3,000 to repair, due to the need to replace parts like injectors, fuel lines, various pieces of sophisticated hardware and the distributor pump.
A car does not have to be very old for the cost of replacing these parts to be prohibitive and lead to a complete write-off.
Rental companies are also at risk of customers putting in the wrong type of fuel and trying to cover up their mistake. Some blame fuel distributors for not having standard colour nozzles at pumps, as diesel pumps can be a variety of different colours.
The development of advertisements on fuel pumps is also distracting and, indeed, these can sometimes cover up the actual fuel type to be distributed.
Fleet managers are tired of repeating themselves but have to continue reminding drivers of this problem – and precisely what do when the mistake is initially made.