Fuel Gauge Problem?
 

I've had my 2008 3 s Touring for about two weeks and I've notice that the fuel gauge seems to move at a rate inconsistant with the mileage I'm getting.

At my last fill up on 12/9, I pulled in showing 1/4 tank and put in 8.31 gallons. At 1/4 full, it should have taken appox 10.8 gallons. It seems the gauge was reading low. Since then, I've put about 90 miles on the car and I'm showing just over a half tank. I'm averaging about 29 MPG, so something ain't right here.

Any ideas? I would like to have some sort of clue before I call the dealer service department to have it checked out. When the needle hits exactly 1/2, I'm going to gas up again to see if it still seems off. I know fuel gauges tend to be inaccurate, but this seems ridiculous! I'm just looking for a little confidence in what the gauge is telling me.

Thanks!

this is exactly why i reset my trip odometer when i fill up. idk if its a mazda thing or what. when i had my first b3000, i would get about 100 mi each for the first 2 quaters of a tank then only a little over a hundred more for the second half of a tank. my second b3000 i would hit 150 miles per half a tank evenly. the tanks were comparable sizes (only a few tenths of a gallon difference, about 19 gallons plus or minus). in my 3 i am generally getting 200 miles in 3/4 of a tank, then generally hit over 300 by the time the low fuel light comes on.

on that note, after i fill up, my trip computer will say i have 350-370 miles remaining, but will always zero out shortly after the light comes on