When filling your car up with petrol, there is one common mistake that almost everyone is guilty of. While many drivers are taught that squeezing that little extra into the tank after the pump shuts off is good, it can actually harm your car – and cost you hundreds.
According to Plates Express, a motoring expert: “When the pump nozzle clicks, it’s because the tank is full and the system has detected rising fuel levels. Forcing more in doesn’t increase your mileage—it often causes fuel to evaporate or overflow, which is money literally disappearing into thin air.”
In the UK, fuel pumps are all fitted with automatic shut off valves that prevent overfilling. Once your tank is at capacity, the nozzle stops the flow of petrol. If you squeeze the nozzle past this point, fuel can often spill into the car’s vapour recovery system.
This can cause several issues with your car that can be costly to fix. These include damage to the car which can be anywhere between £100 to £500 depending on your car. It can also draw saturated vapour into the engine which will affect your vehicle’s performance.
As well as this, overflowed fuel may evaporate or drip onto the ground, meaning drivers pay for petrol they never use.
For petrol cars, the risk is highest because of the evaporative emissions system, which can easily be flooded by excess fuel. Diesel vehicles don’t typically use the same system, but overfilling still causes problems.
Diesel can expand in warm weather, leading to overflow, wasted fuel, and environmental harm. In both cases, topping off is an unnecessary risk that provides no benefit.
Plates Express said: “Whether you drive petrol or diesel, once the nozzle clicks, stop. With petrol, you risk expensive system damage, and with diesel, you’re likely wasting fuel and polluting the ground.”