Pumping ‘Full Tank’ in a Petrol Station is Apparently Not Recommended

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This should be common to many drivers: you get the pump attendant to do a “full tank”, or when you’re pumping yourself, you continue to squeeze in more petrol even after you’ve heard the first click (to indicate that it has auto-stop as the pump has detected that it has reached the limit of the tank).

Well, since you’re in the petrol station, might as well fill the petrol tank to the brim, eh? Or if you’re a Singaporean in JB, obviously you would want to pump in as much petrol as possible, given the lower price.

Well, here’s the thing: your petrol tank isn’t exactly designed to be overfilled. One of these days, you might just see petrol leaking out from your petrol cap. If you think that’s uncommon, you can just ask any pump attendant.

It’s so common that they have often advised customers to just pump it until it auto-stops, not because they’re lazy to squeeze in another litre, but they know what’s going on.

Okay, other than the fact that it might damage your car, you might find yourself in a dangerous situation instead. The thing is, petrol does expand and contract due to temperature, and if your petrol is hot, filling it to the brim might seem okay initially, but a few seconds later, even after your cap is closed, the petrol will still leak out because of expansion.

Having petrol on your car or on the ground is a major hazard because all one needs is a cigarette butt and your car will be a fireball.

The best way to prevent this is to simply stop pumping once the pump auto-stops, as it’ll allow some leeway for any expansion to occur.

Most importantly, it’s never designed to be filled to the brim anyway: why risk it?