It’s not often that a viral video that gives you giggle fits leads to learning an actual useful piece of information, but it does happen sometimes. Today’s important lesson: how to determine which side of an unfamiliar car the gas tank is on before you park on the wrong side of the pump and make an idiot of yourself.

Not that I’ve ever done that while driving a rental or a friend’s car. You haven’t, either, I’m sure. This post is for all of those other people. Like this woman somewhere in the United Kingdom, who is having some trouble figuring out how to make her gas tank leap from one side of the car to the other.

We admire her determination, but there may have been an easier way. You see, in most cars, there’s a subtle indicator of which side the fuel tank is on. It’s so subtle, you may have been paying attention to it without realizing it every time that you get in a car. There’s an arrow next to the picture of a fuel pump on the gas gauge that points toward the side of the car where the fuel pump door is. Simple.

Obviously, not everyone does. Also, the system isn’t perfect: there’s no arrow in this 1997 Nissan Altima, or in this newer Honda Accord, or in this VW Golf. Where you don’t see an arrow, the car-maker may have taken a less subtle approach, like this one that actually says “FUEL DOOR.” My car, which has the fuel tank on the passenger side, does this.

Keep that in mind the next time you’re driving an unfamiliar car. Or try doing laps around the pump and checking the same side repeatedly. That might work.

I’m sure my petrol cap was on this side [YouTube] (via Gawker)

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