Your are in a car, you want to fill the fuel tank of car by going to fuel filling station, you have no idea which side of the car fuel tank is located. Then generally car driver try to get down of the car and find which side fuel tank is located.
Small arrow beside fuel tank symbol on fuel meter indicates the side of fuel tank of your vehicle.
Here’s how the fuel meters of different vehicles Chevy Cobalt, Jeep Cherokee, Infiniti Q50, Infiniti G35, and Nissan Centra look like.
See the below video demonstration, explains this signal in detail.