bad gas mileage? any suspects?

absolutexk · 03-24-2006, 02:19 PM

Lately, I have been getting horrendous gas mileage. I could drive 80 miles on the highway and a quarter of my tank is gone. Why is this?? Could there be any reasons for this? And before anyone makes any wise comments like, "well then maybe you need to lay off the boost", I HAVE been layin off the boost lately, keeping the boost guage under 0 MPa most of the time. i keep the RPMs fairly low at around 2750rpm b4 shifting and even then the boost is barely comin on. I also noticed that when i first start the engine and start driving like 5-10 miles, my gas seems to go down almost a gallon just for driving the tiny 5-10 miles... Why is this? Is it just my faulty gas meter? or is my car really sucking up that much gas? At best I barely get 100 miles to a quarter tank, and my car is really sucking up the cash in my pocket... i have 42k on the car... oil change is comin up soon, and i just replaced the air filter...? pLEASE HELP me out here, im seriously going broke just to buy gas...

awd>fwd · 03-24-2006, 02:27 PM

Ok, you fill up with around 13 gallons right? 13/4= 3.25 gallons= 1/4 tank. 80 miles/3.25 gallons= 24mpg. You aren't getting that bad gas mileage, maybe you should just drive less.

absolutexk · 03-24-2006, 11:56 PM

actually our gas tanks are at 15.9 filled up.. so roughly each quarter is ABOUT 4 gallons x the 27mpg highway, is at 108... but i get nowhere near that

awd>fwd · 03-25-2006, 12:47 AM

Well I have a 16 gallon tank. Fuel light turns on around 13 gallons used up. Don't know about you...

And where are you getting 27mpg... Subaru says my car should get 23 freeway, and I hardly ever see that.

03'WRXDriva · 03-25-2006, 09:02 AM

I got 23.5 once on just interstate driving. and i had cruise set and no hills drivin around 70mph. otherwise i get 18-20. and if i drive real hard in town only ive seen as low as 14mpg. You have to look at your driving style mainly. this isnt a toyota prius or anything now , i have a 06' Jetta TDI that gets 45mpg tho so i dont drive to much out of town in the WRX.

absolutexk · 03-25-2006, 01:28 PM

i dont know about the 2006, but the 2005's are still only 2.0L and the gas mileage is supposed to be 20/27 mpg

gingertooth · 03-28-2006, 07:18 AM

i get about 320 miles on a full tank and you probably do too. a quarter tank of that is 80 miles! (320/4=80). sounds about right to me.

Vew · 03-28-2006, 10:08 AM

I get about 21 in city and anywhere from 26-31mpg on the interstate. Check to make sure you did all your routine maintence and that your car isn't in a limp mode or anything like that. O2 sensor is also something you might want to inspect. Any mods?

Best way to track your MPG is to do it at every fill up. I save every reciept for this purpose... and that my friend's dad almost got arrested for "not paying for gas" even though he did and it was the machines fault. Luckily he had his reciept. Anyways, fill up the tank full all the time. Don't fuel past the autostop. (helps if same pump and same station, but the difference is negledgable). Reset your trip meter after filling up everytime. Before you do, record the miles you've traveled. Divide those miles over what you just filled up. Voila, MPG. Consistant, accurate, and no more guessing with that fuel gauge. You might have to wait until your 2nd fill up if you don't record the miles you travel on a new tank already.

azulwrx · 03-29-2006, 12:11 PM

I drive from Flagstaff, AZ to Albuquerque, NM on the weekends in my 04 WRX and I fill up in Flag and I use just about the whole tank by the time I get to Albuquerque.

absolutexk · 03-29-2006, 07:49 PM

then can anyone explain why my gas meter goes down every time i start up a cold engine and drive 3-4 miles down the road? i can estimate that according to the gas meter about a gallon has been wasted on starting a cold engine including 4 miles of driving...

mosc · 03-30-2006, 11:07 AM

the gas guage sucks obviously. It's entirely inaccurate. Compute miledge from the odometer and the pump when you fill up, not from the gas guage

absolutexk · 03-30-2006, 11:13 AM

i see... so after all its inaccurate... are there aftermarket gas gauges?

bigbadbuddha · 03-30-2006, 11:18 AM

Lots of guages available, but I don't think they are really worth the money and time. Just remember that your bottom half is "smaller" than the top half of your tank.

DOUBLEUAREX · 04-19-2006, 11:19 PM

I map my gas mileage from same pump (auto shut off) fill up to exactly when gas light comes on and I've found that there are a lot of variables that contribute. I've experienced your gas gages behavior in most of the cars that I've had. Almost like some ones been stealing gas. Even though I have a gated drive way and my cars in the garage.

nx2kta · 04-20-2006, 12:02 AM

i get close to 400 hwy miles and that in a 06 sti