Gas gauges in almost every modern car have a tiny, easily ignored triangular arrow right next to the fuel pump icon that points directly to the side of the car where the gas tank cap is located.

A fixed marker, not a fuel warning

The small arrow beside a dashboard fuel-pump symbol is a static location cue. It does not measure the tank or change as the fuel level falls; the gauge’s needle or bars show how much fuel remains. The arrow simply tells the driver which side of the vehicle has the fuel door.

That distinction matters because there is no universal side for the filler. Manufacturers place the tank and fuel door according to the vehicle’s layout and design, so a driver switching cars cannot safely rely on habit. The marker gives the answer at a glance, without requiring the driver to remember a model-specific detail.

A tiny cue for an unfamiliar car

The arrow is especially useful in rentals, borrowed cars, and shared vehicles. Drivers often notice the fuel gauge only when they are already approaching a station, when checking the door in advance may not be convenient. A small, consistent symbol lets them choose a pump lane before pulling in.

It also avoids a common mistake: choosing a lane based on where the fuel door was on the last car. The dashboard turns a hidden exterior detail into a quick decision, helping the driver line up correctly on the first try.