There is no particular reason why car manufacturers install the gas cap on a specific side. The engineers place the doors of the vehicles according to their convenience and as best suits the car model
The gas cap is an essential part of the vehicle’s fuel tank. This element has fundamental aspects to take into account with regard to the safety and integrity of the gasoline tank.
Each car manufacturer designs its vehicles in the way that works best and in the way that is most convenient for its customers. In this way, the marks accommodate the gas cap on a different side.
Some car companies install the gas door on the left side while others on the right. There is no specific reason for car manufacturers to follow this and there are no specific rules or regulations to place the door on both sides. So vehicle manufacturers can put the gas cap on whichever side feels right.
Why don’t all cars have the gas cap on the same side?
There is no specific reason for car manufacturers to follow and there are no specific rules and regulations to put the gas cap on both sides. So vehicle manufacturers can put the gas door on the side that seems perfect to them.
The fuel tank design is the most important when mounting the door on either side. Manufacturers take location and structure into account when designing the fuel tank door. It is a must for underbody packaging of all accessories under the vehicle.
Some vehicles pump gas from the left side so they have a gas tank on the left and the same goes for cars that have a gas tank on the right side. Automakers run this process to facilitate the underbody packaging of vehicle components. So automakers decide the location of the gas tank to facilitate the fuel pumping process and this decides the location of the fuel filler cap of gasoline.