My 2004 V6 Mustang was filled up early friday. I have driven 60 miles and its already at half tank. I filled it up all the way. Also, when the meter says the gas is empty and i fill it up, it only puts in 12 gallons and it holds 16 gallons. another thing, what is o/d and do you want it on or off? PLEASE HELP!!!!!!!!
Horrible Fuel economy!
- Thread starter 3.9stang
- Start date
That is terrible economy!
Check for some things for us (may sound silly, but...)
Is your e-brake on?
Are your brakes dragging?
This could be a direct result of your overdrive being off and you taking a high-speed drive for a length of time.
What are your driving habits? If you are above 45 to 50 mph for a while, you need to have overdrive on so your vehicle can engage 4th gear. It's OK to run with overdrive off in town or when driving in a spirited fashion.
It's safest, when in doubt, to just leave overdrive on, so your car can shift on its own.
Check for some things for us (may sound silly, but...)
Is your e-brake on?
Are your brakes dragging?
This could be a direct result of your overdrive being off and you taking a high-speed drive for a length of time.
What are your driving habits? If you are above 45 to 50 mph for a while, you need to have overdrive on so your vehicle can engage 4th gear. It's OK to run with overdrive off in town or when driving in a spirited fashion.
It's safest, when in doubt, to just leave overdrive on, so your car can shift on its own.
'66 coupe
Founding Member
Are you parked on a hill?
Is your car leaking gas?
I can't think of any other reason the car would be getting less than 8mpg.
Chances are, if he doesn't know what O/D is, he's not turning it off, so that can't be the problem. And even if it was, he'd have to of gone 100mph for that 60 w/ O/D off to get that MPG.
I'm putting my money on the hill theory. Parking on hills can do funny things to gas gauges.
Is your car leaking gas?
I can't think of any other reason the car would be getting less than 8mpg.
Chances are, if he doesn't know what O/D is, he's not turning it off, so that can't be the problem. And even if it was, he'd have to of gone 100mph for that 60 w/ O/D off to get that MPG.
I'm putting my money on the hill theory. Parking on hills can do funny things to gas gauges.
Leave OD on, all the time.
When was the last tune up done? Fuel filter, spark plugs, plug wires?
I'm also willing to bet that since you said when your needle shows E you still have 4 gallons left, that either your float is bent, or your gauge is wrong.
When was the last tune up done? Fuel filter, spark plugs, plug wires?
I'm also willing to bet that since you said when your needle shows E you still have 4 gallons left, that either your float is bent, or your gauge is wrong.
The console shifter indicator should show three positions for forward moving gears (Low or 1, 2, and D). It's been a while since I've been in a 6'er, so forgive me if I'm mistaken.XJay said:
Nonetheless, the O/D switch should be on the side of the shifter and you should have some indicator on the cluster that O/D is off.
shallowreef
New Member
i thought that mustangs have only 13 gallon tanks? Whenever i fill up my car its usually around 12.8-12.9 gallons
You may want to try and actually meassure your fuel economy. Trying to measure your fuel economy by the guage position and your trip odometer is a poor way of doing it. I find that the fuel guage in my old v6 was terribly inaccurate. It could vary as much as a quarter of a tank.
To measure your fuel economy reset your trip odometer before your next fill up. When you fill up make sure you do not top off the tank at the pump (dont add more gas once the pump first stops). Then drive it until you need to re-fuel. When you go to fill up again make sure to not top the tank off again. Then compare how many gallons it took to fill and how many miles you have driven since then.
I would highly doubt you would be getting like 8 mpg and not notice anything being wrong with your car.
To measure your fuel economy reset your trip odometer before your next fill up. When you fill up make sure you do not top off the tank at the pump (dont add more gas once the pump first stops). Then drive it until you need to re-fuel. When you go to fill up again make sure to not top the tank off again. Then compare how many gallons it took to fill and how many miles you have driven since then.
I would highly doubt you would be getting like 8 mpg and not notice anything being wrong with your car.
I have a 99 v6 5 speed and i also get horrible fuel economy. Around town i get about 12-14 miles/gal.
However, if i look at how the gauge reads, the economy looks a lot worse. The needle will move back and forth about a quarter of a tank for absolutely no reason, and often reads lower than the gas really is.
Try to measure your fuel economy by using a full tank and seeing how far you drove.
I replaced the plug wires, spark plugs, and fuel filter. I can get 24-27 on the freeway but still get 12-14 around town. (and no i don't have a lead foot) Does any one know how i can boost my mileage? If so please help.
However, if i look at how the gauge reads, the economy looks a lot worse. The needle will move back and forth about a quarter of a tank for absolutely no reason, and often reads lower than the gas really is.
Try to measure your fuel economy by using a full tank and seeing how far you drove.
I replaced the plug wires, spark plugs, and fuel filter. I can get 24-27 on the freeway but still get 12-14 around town. (and no i don't have a lead foot) Does any one know how i can boost my mileage? If so please help.
zincyellow03
New Member
A tune up should help. My fuel economy also blows 
Damn snow, it's too cold for me to change all that stuff...I got see if I can steal a friends garage for a while...
Damn snow, it's too cold for me to change all that stuff...I got see if I can steal a friends garage for a while...
b52yellow
New Member
naaaahhhhh, he probably has something wrong w/the needle or float inside the tank........ALWAYS reset your TRIP odom. when refueling that`s the easiest way to find out. Also the driving habits depending on your FOOTVELOCITY.......if you can get 250 miles of a full Tank there`s nothing to worry about.......I was also getting it BAD but not worried any more 200-250 miles from a Tank it`s all GOOD for me.(78000 miles-and going..........)I usually drive a week w/a full Tank more often less........Got to let loose of that pedal but who can RESIST.
98CobraClone
New Member
trock
New Member
i dont normally run down to E but i normally get about 190 to 200 miles on 11 gal. Not to bad but not impressive by any means.
when your gas guage is on e there is a reserve built in to keep idiots 
from running out. you have about 3-4 gallons left when on E.
anothe way to find out your fuel mileage can be done if your under warrenty, or if your out of warrenty and you don't mind paying for it.
request a road test with a tech at a ford dealer and ask that they test fuel economy with the WDS scan tool. the WDS has a fuel economy test that gives you real time economy. I have used this many times to show customers that it's how they drive, not the car causing the problem.
I have had several times where i have gotten 5 or more MPG than the customer ( some people go up and down on the gas and can't keep a steady foot)
from running out. you have about 3-4 gallons left when on E. anothe way to find out your fuel mileage can be done if your under warrenty, or if your out of warrenty and you don't mind paying for it.
request a road test with a tech at a ford dealer and ask that they test fuel economy with the WDS scan tool. the WDS has a fuel economy test that gives you real time economy. I have used this many times to show customers that it's how they drive, not the car causing the problem.
I have had several times where i have gotten 5 or more MPG than the customer ( some people go up and down on the gas and can't keep a steady foot)
Skymarshal
Member
360 miles on one tank on my last road trip! 
26 MPG. My record is 29.9 MPG (huge tailwind).
The Mustang has a 15.4 gallon gas tank. It's worth it to know just how much fuel you have left when the needle reaches "E", and you can figure that the next time you fill up. When the needle reaches empty, fill up, and subtract the amount it takes from 15.4. That's your reserve. If you get 25 MPG, multiply your reserve by 25 to see how many miles you have left to find a gas station!
26 MPG. My record is 29.9 MPG (huge tailwind).The Mustang has a 15.4 gallon gas tank. It's worth it to know just how much fuel you have left when the needle reaches "E", and you can figure that the next time you fill up. When the needle reaches empty, fill up, and subtract the amount it takes from 15.4. That's your reserve. If you get 25 MPG, multiply your reserve by 25 to see how many miles you have left to find a gas station!
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