Very low mpg could there be a hole in gas tank?

Fuse leak would reek of gasoline!

Hello, if there was a hole in the gas tank, you would have an extremely strong fuel odor and a leak to the ground. This is highly unlikely. Fuel economy concerns are likely caused mostly first by driving habits and conditions, and then secondarily due to vehicle maintenance. If you have a warning light for your engine illuminated, it could be an indication of something that has malfunctioned causing lack of efficiency. Since you did not mention a light, it sounds like this is unlikely.