An 84-86 Fiero fuel tank has about 7 to 7 1/2 useable gal of fuel. The rest is lost in the filter, lines, etc.. If you adapt an 87-88 tank they hold a couple gal more.

As far as the reading, you could need a new sensor, but they are a pain to replace. I would suggest you not run it below 1/4 tank. You gotta fuel more often, but watch the faces of the folks at the next pump when you fill up for less than $20!!

The range in most Fieros is just a couple hundred miles. When on a long cruise, the club usually tries to stop every hundred miles or so to allow members to fuel up or top off.

Hope this helps

G