There is no universal rule requiring every car to have its fuel door on the left or right. Automakers choose the location based on the vehicle’s overall engineering. Under the car are the fuel tank, exhaust system, suspension, wiring, brakes, and structural components, so engineers must find the safest and most practical route for the fuel filler neck. Depending on the design, that route may work better on the driver’s side or the passenger side.

Manufacturing and safety also influence the decision. Moving a fuel door can require changes to body panels, fuel lines, and the assembly process, so manufacturers often keep the existing design when it already works. The fuel system must also protect against crashes, fuel leaks, fumes, and heat from the exhaust. These requirements are more important than making every vehicle place its fuel door on the same side.

That explains why even vehicles from the same brand can have fuel doors in different locations. Different platforms, wheelbases, exhaust layouts, spare-tire wells, and frame structures can leave engineers with different options. The passenger side is not necessarily better or worse; it may simply provide the cleanest and safest solution for that particular vehicle.

Fortunately, drivers do not need to memorize every model’s fuel-door location. Check the fuel-pump symbol on the dashboard. A small triangle or arrow beside it usually points toward the side where the fuel door is located.

The next time you arrive at a gas station, look at that dashboard arrow before pulling up to the pump. The different fuel-door positions you see are not random—they are the result of individual engineering and design decisions.