3 reasons why your car s fuel cap is on the left or right

3 reasons why your car’s fuel cap is on the left or right

There are three reasons why the fuel cap is where it is, one more plausible than the other

Christopher Ng Photo

Christopher Ng

4 Oct 2018

Have you ever wondered why some car requires you to pour fuel on the left while some need you to be on the right? No, this isn’t some vile scheme that car manufacturers play to mess with your mind. The reason, of course, is more logical and indeed less sinister than that.

There are three reasons why some cars have the fuel tank filler pipe on the left and some on the right.

1. It has to do with safety
You may have already noticed that most German cars have their filler caps on the right while most Japanese makes have it on the left. This has to do with which side of the road the cars are driven on, thus, influencing the placement of the filler pipe. The rule of thumb is this; the filler cap is placed on the same side as the front passenger but because we drive on the left, the filler caps are on the driver's side instead.

Imagine you ran out of fuel and your car is parked on the side of the road. Now imagine you’re pouring in fuel from a large soft-drink bottle into the tank. If your filler pipe is on the left side of the car, you’re safely away from traffic. If your filler pipe is on the right, then you’re the closest to the speeding vehicles. But if you're in an European country, or even Korea, then the opposite is true.

2. Less waiting time at the pump
There’s another school of thought that requires you to imagine a world where all cars have the filler pipe on the same side. It would mean that only one car will be able to fuel up, thus, creating a queue longer as those seen during the good old days of managed float fuel prices. This really isn’t efficient. 

Having fuel tank filler pipes on either side of the car means that two vehicles can fuel up at the same pump at the same time, one taking the left nozzle and the other on the right. This school of thought calls this a ‘state of equilibrium’.

3. All about the car’s packaging
In a post on an American insurance website, the placement of the filler neck depends on how the vehicle is packaged. There will be times where certain features in the car could get in the way of the filler pipe. So, instead of sacrificing the element, some manufacturers will break rank and have the filler pipe on the other side. This may explain why Subaru, a Japanese carmaker, have their fuel caps on the right instead of the left.

No matter which reason you chose to believe in, one thing remains true - the placement of your fuel tank filler isn’t a random choice.

Sources: PBS Newshour | Allstate Insurance Company | Jalopnik
Story by CT