The average household has 1.88 cars. This means that you are faced, sometimes if not always, with filling up two gas tanks. On which side is your fuel door? And once you’ve answered that question, answer this one: why that side? Because you’ve asked yourself that question many, many times.

Explanations run the gamut of utilitarian and functional:

My dealer told me that all Subarus have their gas intake on the passenger side for safety. In case you run out of gas and have to fill up with a tank on the side of the road you’ll have your car as a barrier between you and the traffic.

This is very smart. It also suggests that American cars would inevitably have their tanks on the passenger side. Which, of course, they don’t. In fact, the obvious solution was to put the filler in the middle of the car’s rear:

Once the cheapest, most convenient solution, the middle, was made illegal, everything became a nightmare of relativism and equally rational justifications. Both sides have their advantages and disadvantages, and we’re left, wandering, alone, confused.

The truth, though, is that there are simultaneously many reasons why your car’s fuel filler is on the side it’s on and there’s also as many reasons why it could be on the other side. There is no one answer, and anyone who attempts to find one is on a path that only leads to madness.

Why Some Cars Have Gas Tank Fillers On The Left Or The Right (Jalopnik)