An oddity about the iQ ...
Not only does it have one of the few flat gas tanks in the auto industry, but it has a very odd capacity of 8.5 gallons / 32.2 liters.
This makes it very difficult to estimate how much gas is left in the tank.
Each of the 6 “marks” for capacity represents 1.41 gallons
One remedy for this is an OBDII device that indicates “Miles left to travel” fuel efficiency.