when i fill up it doesn't go to the full mark. i bought the car a few months ago and it used to go to the top but now it doesn't. i also am only getting about 250 miles per tank. i am not car smart but i am interested to learn and do it myself. please help!

 

How are you calculating your mileage? Are your tires properly inflated? No alignment issues? Change of driving route/style? Crap winter gas? Ethanol laden fuel(E85) can degrade fuel economy.

 

it usually takes around 14+ gallons to fill up. when i got the car i used to go around 350 to 400 miles to a tank and now it is around 250. same winter gas since i got it in november. Allignment is good and it has brand new tires with good pressure. i do alot of highway driving and i did change the fuel filter about a month ago. i have tried addatives and driving like grandma but no change.

 

Is the car an auto or manual? Do you smell gas when the car is running? When was the last fuel filter replaced? Tune up? Dirty air filter, EGR ports and valve cleaned, lastly, O2 sensor (Denso or NTK only, Rockauto has the Denso for $29 shipped). Does the car idle higher than normal?