Does filling the tank to the maximum during heat waves induces a explosion risk?

Question

I recently saw a picture stating that filling your tank to the maximum during heat waves may induce an explosion.

The transcript of the picture :

Warning !

Due to increase in temperature in the coming days, please don't fill petrol to the maximum limit. It may cause explosion in the fuel tank. Please fill the tank about half and allow space for air Don't just read the message and stop. Let others and your family members who drive also know about it so that they can avoid this mistake... PLEASE DO SHARE THIS MESSAGE.

The picture comes from PSO "Pakistan State Oil". I don't live in Pakistan, but in western Europe.

My question is : Does filling your tank to the maximum induce a risk of explosion ? If so, at what temperature is it meaningful ?

My feeling is that the goal of this picture is to generate likes and shares and that the risk of explosion is non-existent.

-Tanks are designed to withstand pressure and the pressure difference from the temperature won't be significant to make the tank burst.

-Letting air into the tank adds oxygen, a tank full of petrol would be safer without oxygen.

-If the car runs on diesel, the pressure won't be sufficient to ignite it.

Answer 1

As you suspect, it's a myth - there's no increase in risk in hotter weather, as all fuel tanks have vents (if they didn't, you'd not be able to fill the tank as there'd be no way for the air in it to escape as the fuel rushed in, or in fact to use the fuel, as air has to be admitted in order to replace the fuel as it's used)

If anything, a full tank would be safer than a nearly empty one, as it's the vapour that can explode (in the case of petrol - Diesel needs high compression to ignite)