Okay the manual for my 1990 Accord DX says that it holds 17 gallons of gas. It was just about on the line for empty today, and I put 30 dollars in and the pump stopped filling and its right under the full line. And at about 3.20 a gallon 30 dollars is like 9.9 gallons. Now I'm pretty sure there wasn't 7 gallons left in my tank, nor can I fit much more. If I had to guess I'd say the capacity is like 13 gallons. Why does every place I've read say 17?

 

It is 17, unless you have a big dent in the tank. Maybe the pump shut off before the tank was full. Have you ever run out of gas? The gage needle goes down farther than you might imagine.