Was wondering why my 03 wrx is wasting so much gas. Car is completely stock. I just drive 20miles and it wastes over a quarter tank. anyone think/know what could be the problem? thanks

 

fuel pump?

 

Did you buy the car new? Has the car ever gotten better fuel economy? Is the vehicle regularly maintained with scheduled oil changes, spark plugs, checking tire pressure, etc.? How would you describe your driving habits? What sort of driving conditions to you experience during your normal commute or everyday driving (heavy urban traffic, open freeway, hilly terrain, etc.)?

Let's see how bad your actual gas mileage is:

Take note of the odometer reading. Fill up the tank until the gas pump nozzle clicks off automatically. Do not top off. Drive normally until the tank is at least half empty, then refill at the same gas station/pump again. Now calculate actual gas mileage by dividing miles travelled since first fillup by exact number of gallons (to at least one or two decimal places as displayed on the gas pump) it takes to fill the tank the second time.

The Impreza dashboard gas gauge is not a precision instrument. The needle sweep does not move linearly proportional to the amount of gas remaining in the tank.