Many drivers acknowledge that they have never actually seen it, but the arrow on the fuel tank pointer is extremely useful. Specifically, it indicates the side where the fuel tank cap is located.
Of course, in a private car you use every day, it loses its meaning, but in a company fleet or at a rent-a-car veichle this information can be extremely useful
The following rule usually applies;the manufacturers of the countries driving on the right side of the road, put the fuel injection cap on the right as well.This makes it easier for the driver to leave the car. Japanese and Korean manufacturers put it mainly on the left.