I've gone through half of a tank, and I've only driven 68 miles. That's total bullcrap. Why am I getting terrible gas mileage?

I checked the air filter, it's okay. I'm thinking about deleting the airbox, because whoever had it before me was an idiot and it's all sorts of not okay. However, it should be getting airflow... Any ideas, anyone? A checklist would be cool, I'll just go one by one finding the issues.

Also, does anyone think a 2003 SE Auto with 122,xxx miles is even WORTH modding? Ex: Airbox mod, body mods, throttle mods, ECU mods, engine swaps, etc... How hard would it be to swap this car for a manual trans?

 

sounds like you're leaking fuel, not burning it... my power boat burns alot gas, but not that much.. You'd have to be getting a ton of black smoke too even if it were to burn that much. Check for the obvious or you've had your tank siphoned by a gas crook/thief

 

How many miles are you getting on a tank? Some gas gauges drop fast initially and then slowly on the last half of the tank. For example: my Mustang will only go like 70 miles on the first half of the tank, according to the gauge. However, on a full tank (when the needle finally goes to E), I'm at around 260 miles or so. If you are only getting 140 miles or so on a tank, you are leaking fuel or it's being stolen.

 

In addition to the above, also check plugs and oxygen sensors may be going bad. Also, look at your tires and check pressures in each.

Is it worth modding? Not in my opinion. It's just very limited in what you can do. You could do an SRT swap which is well documented here but by now I'd think good quality used parts have dried up a lot.

 

as darthroush said, this can happen, best way to check is as follows

1> fill the tank and stop on the FIRST click
2> (should be somwhere around 40 litres from empty)
3> ZERO the odometer
4> run car normally, keeping the rev's at no more that 3000rpm, constant easy driving
5> When the fuel tank starts getting into the red, as soon as the tank low warning light comes on, get it to a gas station (think you've got about 30kms)
6> Fill up and stop at the FIRST click
7> you now know HOW many litres of gas you put in and HOW many km's you drove
(work out the MPG - online calculator)


NOW, do the basic's

1> do a basic service, oil change, change the plugs (copper), change the leads, the A/F

2> CHECK the tires, make sure they are the CORRECT PSI's

3> DONT use the A/C (well its winter but it increases the MPG)

4> Snow tires also increases the MPG

redo the test

as a help, these are my figures

STANDARD NOTHING DONE
epa says 21 city 24 comb 29 hiwy US Gallons

FULL TANK 407KM'S 38 LITRES
30.26 mpg uk


Full tank 416km's 38 liters (after a service and goodyears/winter)
30.93 mpg +9km's extra

Full tank 433km's 38 liters (SUMMER Continental / all season)
32.19 mpg +26km's extra

Full tank 503km's 38 liters (Continental / SERVICE (WHEEL BEARINGS, MOUNTS, ALIGNMENT, PCM/TCM / COPPER SPARKS )
38 mpg +96km's extra

hope this helps

 

dont delete the airbox, i've read all over the place about this and theres 2 camps, basically IMHO, your car was designed to be safe, economical and last, they do try and get as much "horses" out of a car, I wouldnt mess with the airbox because injecting the wrong airflow messes around with the programmed settings

I drove several performace cars (including a Porsche) and never messed around with that on any of them

its an 03 neon,

 

I'm working on recording my MPG right now.

Real quick guys, my air box has broken mounts. Whenever I give it gas, it moves. The more I throttle, the more it moves to a normal position. Does anyone else's move??

Also, I want to add open door lights. Anyone know where the closed door switch detector is?

Thanks guys! New car, I'm a bit ambitious.

 

no my airbox doesnt move

 

It could also be a problem with your plugs/wires...happened to me before.

 

Does your engine move as well

WORTH depending on your economic state is and how much you enjoy your care it might be WORTH doing some thing.

I wouldnt suggest an srt4 swap unless you have a close mechanic.
Its a lot of work, parts, money and time.