[KevinJ99GT]

all i have that would hurt gas mileage is 4:10s...is 16 in town and about 19 on highway very very bad? I do tend to get on it every once in a while

[Cricket]

keep it below 2500 rpms.

[03FstStngKB]

Nope not bad at all...I get around 14 to 15 in town and 20 on the highway but I have 4.30's. Like Cricket said keep the revs low if you want to get more mpg and don't take off fast all the time...kinda defeats the purpose of enjoying a fast car doesn't...lol. But if your after good fuel economy don't get on it all the time and keep the revs lower...that should work in most instances.

[BuRnIn_YoUrS]

Lol i feel your pain man...i spent one whole tank shifting between 1500-2000 RPMs and never got on it...sadly i only got 208 miles out of the tank...idk what the hell is up

[casper gt]

better than I'm getting with 4.10's/auto

[03FstStngKB]

If you're really wanting to squeeze a couple more miles per gallon out of your tank...check your spark plugs and change your fuel filter and maybe even your air filter. Just be careful taking your plugs out if you haven't messed with 4.6's aluminum heads before...they can give you problems if the plugs are not torqued right. Also tires need to be inflated properly too. There is a number I've heard before but for every pound of underinflation you lose x amount of gas(mpg)

[BuRnIn_YoUrS]

Yeah i just put a new air filter and fuel filter in. I did hear about the spark plugs which was why i'm a bit hesitant about doing it. I kinda think that i need new plugs.

[03FstStngKB]

Originally Posted by BuRnIn_YoUrS Lol i feel your pain man...i spent one whole tank shifting between 1500-2000 RPMs and never got on it...sadly i only got 208 miles out of the tank...idk what the hell is up

I remember in my 91 5.0 GT most of the time I could not even get 180 miles out of the tank...that equates to about 12.8 mpg...never would let it go bone dry most I ever put in the tank was like 14 gallons...think the tank was 15.4 max...same as the 99-04's?

[v606er]

with the mods in my sig, i have gained about 50 miles per tank, so thats about 3mpg better in town (now 20mpg... 280 miles per tank, 14 gallons. and thats still having fun driving). now im thinking i wont lose more that with 3.73 gears, so ill be happy

[B0B]

sometimes i don't understand how horrible the mileage is for some people! i can drive my car hard and get 19 around town.. and EASILY get 26 on the freeway.. up to 28 if i'm careful.. with 380+ to the wheels.

[03FstStngKB]

Originally Posted by BuRnIn_YoUrS Yeah i just put a new air filter and fuel filter in. I did hear about the spark plugs which was why i'm a bit hesitant about doing it. I kinda think that i need new plugs.

Yeah I just got done doing a lot of work to my 90 honda accord which is my daily driver...changed the transmission fluid, plugs, airfilter which had a birds nest stuck to the back of the filter...couldn't believe that one...lol...but pretty much did every little thing I can think of. I was getting 25mpg in the city and about 33 mpg on the highway so I will see if it helped? I do know that my honda is geared up...lol. It has got some pep to it even though it's only a 4-cyl. It is front wheel drive but the final ratio that is on it is 4.30. I found that out by doing some deep reading on the net. I turn about 2800 rpms in 4th gear at 70 mph on the honda...I know I could do a lot better with my fuel economy in the honda if I was turning less rpms but oh well...lots better than what the stang does.

When I changed the plugs on my honda...I finally got to feel how much 13 foot pounds of torque is...lol. Not much...I can tell you...that is the recommended rating for the plugs on my honda and I think that is real close to what the mustang's are too? My dad was standing next to me and when I was using his torque wrench I said...did you hear that click...lol. I was like I barely moved that wrench before I heard it click...lol. Anway I was like I was going to see if I could unloosen them with my hand...sure not I couldn't...but I was like damn...how many people do you think overtighten them? I can see why so many people have problems? It would be real easy to overtighten unless you really have a good feel by doing it alot times with a torque wrench.

Then there is a whole nother issue with the weak thread count on the heads itself. I'm kind of leary of doing them too but I will probably do them next year...I am just shy of 60,000 miles on my car and won't put enough on the car before the end of year where it will be garaged for winter...only taking it out during nice weather or to just start it.

[BuRnIn_YoUrS]

eh i got torque wrenches here at work...i guess i could man up and change them.lol

[mrbigjeep]

Originally Posted by BuRnIn_YoUrS Lol i feel your pain man...i spent one whole tank shifting between 1500-2000 RPMs and never got on it...sadly i only got 208 miles out of the tank...idk what the hell is up

you could have other problems but try not to shift below 2000. shift right at 2K or just a little over (but still under 2500) that way you don't bog the motor and use more gas by lugging the motor up to speed.

i have an 04 gt also and get waaay more than 210 a tank.

[03FstStngKB]

Originally Posted by B0B sometimes i don't understand how horrible the mileage is for some people! i can drive my car hard and get 19 around town.. and EASILY get 26 on the freeway.. up to 28 if i'm careful.. with 380+ to the wheels.

Maybe you have a factory freak...lol. I dunno why is red look red or black look black...not trying to be a smart ass but sometimes your just dealt with the cards you have and no matter what you do you cannot change the outcome. I am sure there are things that can help improve fuel economy to a certain point but just like some cars stock will dyno higher than other cars will and some will dyno lower. I guess there is a threshold on what car makers expect the rate of gas mileage to be...and no one can factor in the way a person drives a car...there are too many factors to determine what the gas mileage will be or expected to be for any given person. There should be a range that everyone should fall in and if you're out of that range well then something needs to be done to fix it to get you back in an acceptable range.

[BuRnIn_YoUrS]

Yeh i usually never shifted at 1500...it was actually more like 18 or more, fifteen seemed too much. I know using the AC kills it...but when you leave for work at 230 in the afternoon after gettin in a leather interior thats been in the sun all day, wearing the hot ass BDU uniforms, i can't help but to use it. it blows here

[ReverendDexter]

I'm stock outside of an airfilter, I get 16 around town, and usually get 22 on the highway. I got 26mpg on one trip, have never been able to replicate it, though. I make up for the mileage by riding my bike to work every other day, makes it like I'm getting 32 mpg

[B0B]

i do know that when i had my diablo tune my car dropped in mileage dramatically. i could practically watch the needle go down when i was driving. so i put my stock tune back on till i got the supercharger and now it gets about the same as stock if not a tad better. elevation, humidity, and temperature can come into play as well..

[03FstStngKB]

Originally Posted by BuRnIn_YoUrS eh i got torque wrenches here at work...i guess i could man up and change them.lol

Yeah as many threads as I read on stripping plugs or the backing out of plugs from the heads and the such is about the only time I gave notion to a torque wrench. I am sure if you are going to build an engine...that would be a good time to use one too but Ford did not help out either by using very little threads in the head...from what I hear?

[BuRnIn_YoUrS]

your probably right...Freakin ford.

[03FstStngKB]

Originally Posted by BuRnIn_YoUrS your probably right...Freakin ford.

I know my 91 5.0 had cast iron heads and I had a plug in one cyl. foul up so bad that I had to clean it all the time. When I took that plug out I tighten'd that b*tch as tight as I could...lol. I think I might be in trouble if I did that on my 03...lol. I just wanted to make sure they would never come out...luckly I never snapped a plug by overtighten that one plug in my 91 but I'm so glad that I have read so much on the 99-04's and everyone's problems is the key to you or me to getting it done right the first time...if you know what I mean or at least having an idea of what could go wrong.