I've owned my 2005 Gen II Prius for almost 2 years now. I normally average around 45 MPG on each tank of gas; however, the issue I'm having with my car is it seems that I'm unable to completely fill up the gas tank. The most I've ever put into my car was about 7.5 gallons, and that was with the gas light on and the last brick on my gauge blinking at me. I normally wait until there is 1 or 2 bricks left when I fill it with gas and I average around 300 to 325 miles per "tank". Whenever I fill up my car, I usually put between 6.5 and 7 gallons of gas into it. So, the mileage isn't really the issue, it's that my car supposedly has a gas tank that holds 11.9 gallons in it, but I've never been able to put anywhere near that amount of gas in it. I've done some reading on forums and found out that the amount you can put into a prius is determined by an internal fuel bladder, but I can't imagine that it would ALWAYS be this bad, especially over a 2 year period. Any other ideas as to what could be going on with my car? Thanks in advance!