Just got it the other day has 88k miles put 30 bucks in and it took me to 3 1/4 of a tank and i have gone 91 miles and its droped to almost quarter now but i noticed that was 7.8 gallons and its a 17 gallon tank theres no way it will be at 3 1/4s of a tank lol my question is, Is it the gas Gauge that's bad and if so how do i fix it?