Some diesel vehicles, particularly Ford’s and BMW’s, come equipped with misfuelling prevention devices. The purpose is straightforward – to prevent the user from accidentally adding petrol to a diesel fuel tank.
Most devices work through a mechanism that only permits the exact diameter of a standard diesel pump nozzle to penetrate the filler neck. Any smaller diameter nozzle, such as that of a petrol pump nozzle, filler funnel or similar, will not enable the mechanism to open the filler flap.
The problem is that the user is then unable to administer fuel additives or fill up from a jerry can in the unfortunate event that they run out of fuel. Well, no need to panic. Most vehicles with anti-petrol filler mechanisms usually have a funnel or insert stored in the boot, usually near the spare wheel. If not, then a suitable funnel/filler insert can be obtained from the local dealer.