Do you fill up, let it go down and divide by gallons?
or do you Fill up, go to half and divide by half your tank?
Either way, my mileage isn't so great. It's in the mid 20's
Any tips beside the usual tire pressure, spark plugs, oil change...

 

I divide my trip odometer (reset at each fillup) by the amount of gas I put into my empty tank. Assuming that I fill up the same way each time, and that the pumps work the same, I should have a pretty accurate estimate of how much gas I used, because you can't put more in than you took out.

 

when you fill up make sure to get a receipt. so if you start at a full tank of gas, reset the trip odometer and whenever the next time you fill up see how many gallon's you actually use to fill it up. with that you need to divide your miles into the gallons and that will give you your mileage. EX= if you drove 200 miles on one tank of gas and you used 10 gallons to fill the tank the next time you filled up, that would give you a mpg rating of 20. here's the math for it. 200 divided by 10 = 20.

 

^^ thats how u do it... its just how much gas you have used since you filled up last then you take this equation: (gas used) / (miles traveled on gas used) = ____MPG <<( thus units are MILES "per" gallon).... i usually get roughly 25-28 MPG on average but i just changed over to royal purple and now i've been getting roughly 27-31 MPG so thats one way to increase gas mileage...oh what the hell lets turn this into a little write-up b/c im sick of saying all of this over and over again:

Introduction:

if you are really serious about your gas mileage and you do a lot of highway driving, use your cruise control (if you don't have it get it) it really boosts your fuel economy up a lot, Iridium spark plugs help out and save you money, also a CAI will help a bit as well as MMI as they help translate more power to the ground thus increasing efficiency of the motor. you can also get a high flow cat. which will increase the burn efficiency as well as reduce back pressure just a little bit which helps the motor "breathe" essentially... those are just a few ways to increase your mileage... things that don't work are:

1) oil additives (they actually hurt your motor as they break down the oil's components that reduce friction, and break down the oil molecules in a lot of cases which makes you need an oil change a lotttt sooner.)
2) fuel additives creates an inefficient burn as they don't create the correct chemical bonds with the fuel you use, thus creating an inefficient burn.

(both 1 & 2 actually may also hurt the longevity of your spark plugs, in some cases it may foul them all together...)

3) Octane Boosters - our cars have a very strict timing map that does not allow for any different levels of octane to be used, so if you have a base model neon (ES, SE, or SXT) you should be using "regular" fuel (87 octane), if you have a neon with the 2.0L "High Output" motor ( r/t ), then you need to use premium fuel (91 - 94 octane), if you are using any other octane then you are going to lose fuel economy. thus boosting the octane is a bad thing to do unless you have a standalone ECU/PCM system in which case you can program for any fuel or octane you wish.

4) Little "Chips" on ebay - these are the biggest waste of money in the world there is NO modification that consists of ONE little piece that will give you an increase of 10 or more HP and a ridiculous boost in fuel economy, most of the time these "chips" are just a wire with a resistor tapped into the line which does nothing but reduce the signal strength which is suppose to "trick" the PCM into using LESS fuel but the problem here is that when the PCM checks the O2 sensor(s) on the exhaust system it can show a dangerously lean air/fuel mixture or an extremely rich air/fuel mixture both of which are bad (lean is MUCH MUCH MUCH WORSE), so when the PCM detects this discrepancy between the inlet sensor system and the outlet sensor signals and the corrections that it implements have little or NO effect, the PCM will then go into LIMP mode which runs the motor directly off of a BASE MAP which basically will cause our cars to run PIG RICH (LOTS OF FUEL USED) and will also in most cases not allow you to rev past, i think 3k or 4k RPM and with Automatic Transmissions you will usually not be able to drive past 40 or 50mph... sometimes less... and running in this mode for more than 30-50 miles will usually result in some costly repairs and a very unhappy wife and wallet...(unhappy wife and wallet comes in pairs btw)... just a little information CHIPS do not work on ANY NEON as they our PCMs are programmed to not allow those types of modifications, use the search feature and you will find a more extensive write-up on these chips.

5) Coolant Additives - these are the same as fuel additives sure they will increase cooling efficiency but they decrease the longevity of the coolant, as you may/may not know our radiators are aluminum, so we need aluminum safe coolants which are generally coolants that are formulated to last for 80k-100k miles, which is a great thing because the cooling efficiency is kept very steady over this long period of time, but when you introduce an additive sure the cooling efficiency is increase for a few thousand miles but the additive breaks down thus causing the coolant's bonds that allow it to last for a long period of time break down causing a dramatic drop-off in cooling efficiency, which can damage your motor and cause a drop in fuel economy, so only use coolant additives if you plan on draining and flushing your entire coolant system at every other oil change (very time consuming and costly).

---- Now a quick overview of what WILL help:

1) Certain performance modifications -
a) Cold Air Intake - increases amount of fresh air that will get to the motor as well as decreases the temp. of the intake air.
b) Motor Mount Inserts - reduces parasitic loss in the drivetrain thus allowing a more efficient burn cycle.
c) High flow cat. - reduces back pressure and allows motor to get rid of the dirty exhaust gasses more efficiently.
d) Iridium spark plugs - hotter spark and longer life as well as allows the car to burn all/mostly all of the fuel that has been injected through the fuel injectors into the cylinders upon each cycle of the engine.
e) Upgraded ignition coil - Allows for a more consistent voltage within the ignition system which will increase efficiency of the entire motor.
f) Upgraded ignition wires - also allows for a more consistent voltage from the coil pack to the spark plugs, and it will also reduce resistance in the ignition system as well which ensures a more complete burn, increasing the efficiency of the motor.
g) Lighter & Smaller underdrive pulley - will reduce the parasitic drag the motor caused by the accessory belt, A/C, Power Steering, Alternator will all suffer a little bit as they will be slightly underdriven but you will see an increase in power especially when the a/c is on, but you may see a drop in the alternators output.

2) Using the correct fluids (fuels, oils, etc.):
a) Royal Purple Oil (5w-30 and/or 10w-30) is proven to increase fuel economy as well as power output, and from personal experience i can and will agree and i will never use any other oil.
b) Use the correct octane 87 for base model neons, and 91 or 94 for neons with the high output motor.
c) Use the correct coolants and transmission fluids and keep them up to date as far as changes go.

3) Driving habits:
a) If you are racing around town in high gears with your foot to the floor your gas mileage will suffer.
b) use cruise control on the highway (if you don't have it, consider getting it, as i personally have gotten 33 MPG using cruise control)
c) Don't excessively idle the car (specially in summer & winter seasons), as it will be wasting a lot of gas over the course of the season(s). Deal with the heat/cold.
d) Close your windows when traveling above 45mph as open windows create wind resistance which will decrease your gas mileage, as it will take more power from the engine to move the car. (i know its hard to do this in the summer or in hotter weather.) in cases where you are going on a longer trip it is actually slightly more fuel efficient to use the a/c sparingly over your trip instead of keeping the windows open.
e) don't use the A/C when you can just as easily open the windows when you are cruising around town.


well thats about all i have time for today ill be adding to this and refining it some more when i get more time to do so.

 

The way you have it is gallons/mile......the guy above you has it right though.

 

well does anyone know how many gallons of gas u can get on a 04 neon tank.
like i once got 7.5 gallons in mine but i can only usuall get 6.5 now probably cause of the rear end being a little lower.

 

well your tank has a capacity os 12.5 gallons. so it depends on how far you let it go to empty. when i fill up, I pump about 10 gallons in to make it full again. but i let it go down pretty much to E, but before the gas light comes on.

 

oh dam i see.lol.
ive tried to let mine go all the way down to E but never have i just let it get close to it then fill up all the way.

so when its really empty the light comes on??

i think ill try to let it go down further than i do to get more miles in.

 

when your light comes on i believe you have like 1 - 2 gallons left or about 50 miles still to go. I'm not 100% sure on that, but its somewhere in that range.

 

thas cool thanks for that info.