The arrow next to the fuel gauge
A small triangle sits next to the petrol pump icon on the dashboard. You may have driven for years without noticing it.
Category: Getting about
Be the first to vote on this one.
Feature. It points to the side your fuel cap is on.
The arrow shows which side of the car the fuel filler is on, handy in a hire car or at a crowded pump. It is credited to a Ford designer, Jim Moylen, who proposed it in the 1980s, and is now common across makes.
Source: What that little arrow next to the fuel gauge actually means, Motor1.