[IRTsti]

Ok, so i've owned the car for 3 fills on the tank. Everytime i fill my gas gauge is halfway between the 3/4 and Full mark making me think the sending unit is off.
First tank I drove and had a blast boosting,not worrying about mph. The 2nd and third tank i decided to see how much i can get driving like a granny with 60% highway miles. So I got 200 when my light comes on and 230 before i get paranoid with the needle being on top of the Empty line.

I dont know how much i can go b4 im actually out of gas but 230 a tank is 14.49 mpg with 5% boosting. Makes me wonder if I seriously need a tune up. I havnt changed the plugs yet and im at 42k. Book says change at 60k. Car runs great though.

[amg destroyer]

This might sound like a wierd question... but do you fill up using the "hi-flow" setting on the nozzle or the "low-flow"? I've found that when I use the high flow setting I get less gas. I'm assuming that the gas is pouring in so fast that it sloshes around in there and messes with the sending unit.

When I use the low flow setting, it reads a completely full tank.

Just some of my observations...

[IRTsti]

low flow, ive read about the gas foam, always search b4 i make posts. The fact the needle wont go full doesn't bother me as much as the 14.5 mpg driving like grandma.

[kb2spn]

There are so many factor swhen filling the tank.......pump pressure,pavement(incline) etc.I can still squeeze 2 gals into the tank after the pump cuts off.My fuel light come on anywhere between 230 and 310 miles.Cruising to Toronto,Ca. @ 75 mph ,I made 400 miles per tank ,I also made 150 miles per tank.

[Bishop]

fill up at night or somewhat early morning, avoid filling during the day or right after a semi fills up the tanks at the station. Set to the slowest fill rate and check your oil or something .... i started doing this and noticed a 1-1.5mpg increase from this alone.... also, i would fill ur car to the brim, run it a while, fill it back up, and divide the mileage from full to current, by however many gallons it takes to fill up.... should give u mpg.... 14 seems rediculous, Rewind gets 15mpg on this forum but hes tuned for E85 and has to fill up alot more than w/ 91 or 93

[KarlSTI]

OK, here's the deal. Fill up the same way everytime and record every tank and mileage for 30 tankfulls. Average your mileage. Never make any assumptions based on 1 or 2 tankfulls....too many factors to make conclusions. I have an 05 STi and the average of my last 300 tanks of gas is 17.9 mpg. It is mostly city driving and it includes 2 autox's each month.

[AARONH]

Buy an AP and use the mpg gauge while you drive. I went from 18 to 21mpg. Oh and my needle does that also, I just ignore it.

[fresh2512]

Man, that does seem low. With driving my car "normal" with minimal to moderate boost I range 22-25 MPG... I know you haven't owned the car long, but you might want change the oil in it. Maybe the previous owner was using the "wrong" oil. Maybe there's some really thick oil in your car? I always use Castrol Synthetic 5W30 with a genuine Subaru oil filter and new crush washer at every oil change. You also might want to pick up some fuel injector cleaner and try using brand name fuel. Not to mention a new air filter! I installed a K&N panel filter in my car and it's a great filter. Anyway, good luck and I hope you get your gas mileage improved!