hey guys, I got my car on sept 12 and have driven 1900 miles on it since. I have a 5at with an injen intake. whenever I check my fuel economy on the navi screen it shows between 8 and 12. I always drive in city, but it's not always bumper to bumper. I rarely get above 2500 rpm, and mostly drive alone so don't have much weight. I only put shell V-power, and have not got an oil change since I got it. I know it's a six cylinder but I did the same driving with my moms jeep grand cherokee and got better mpg with the 4.0. is this normal mpg? I checked the reset interval history and saw the guy before me was getting atleast 16 sometimes even 25. what should I do? I wanna get an oil change, should I get synthetic, like the guy before me? I would hope for atlwast 15 mpg city. also I don't ever fill my tank, usually do around 7 to 8 gallons, when I have filled all the way though, the gauge doesn't reach the top it stays two ticks before full, and also the gauge fluctuates alot. what should I do?

 

I had the same issue in the past. It has something to do with letting the car warm up. I used to just sit at idle til it warmed all the way up... Read a thread in the past that said doing that is terrible for gas mileage. Best thing to do is even on really cold day to turn it on and let it run for about 45 secs to a minute then drive slow on your initial take off. Keeping your RPMs below 2500. After learning this technique my gas mileage is waaaaay better. I used to get 11-12 like you, now I get 19-20 on a mix of HWY & city. Hope this helps. I'm assuming all your maintenance has been done properly & in a timely manner of course... Oil changes, air filter, spark plugs, etc; Good luck bro.

 

An Ecu reset may also help too bud. Goo luck!

 

AzuMaster has some good advice. Check your tire pressures as well. Lots of short trips will make the gas mileage go down as well. Your driving style and mission may be substantially different than the previous owner's, and that can have an impact.

Also the best way to check your gas mileage is not through the nav screen, but rather to fill the tank until the dispenser nozzle shuts off. Reset a trip meter to zero. Drive until nearly empty, then refill until the dispenser nozzle shuts off...preferably at same gas station and same pump to reduce variability. Note the gallons it took to fill it the second time and divide how many miles are on your trip meter by the gallons you pumped.

 

^This. And you will want to do it 3 or 4 times to get a good average.

 

Holy ish my friend, it's like reading about my car. I got it at the end of august, also an 04. I also have the fuel tank issue. It will only fill up to 12-13 gallons (also use shell v-Power). The milage is ok though. On a full tank (lets say 13 gallons I would drive about 230 miles city only. But my gauge also isn't accurate (the light would turn on but after some time go off). Mine is also pretty stock (20" rims and a k&n drop in). I just don't have navigation to check my economy