15mpg...p**sin me off!!! what can i do

SilverFox90

New Member
May 11, 2004
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central, IL
i only avg 15mpg with mixed city and highway driving.....the majority of miles are 5-10 mile constant trips at 55-60mph i also have a decent amount of in town driving and am not real great at keepin my foot outta it....but it doesnt seem to matter if i baby it or not o2 sensors?...i dont get any check engine lights....i only have minor mods which are listed
 
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i dont think that is unreasonable with a sometimes happy foot. if the o2's are old, they could use freshening, but i dont know that it would help as much as you would like. as they age, they dont fluctuate as often or as much (lessened range of fluctuation). HEGO's do last longer than EGO's though.

good luck. (I get 15MPG in town).
 
i have no idea about the fuel filter...guess i should change it anyway...forgot to mention that it has new plugs cap and rotor....anything that i can do to increase mileage?...2$ a gallon for gas is killin me....i spent 70$ on gas in 6 days last week
 
go to a different gas station. drive like an ass. seemed to work for me. going to mobil and driving like a grandma i was still only getting 17 average. i switched stations and now drive more spirited and it seems to be doing better. Well see though when the tank gets down to nothing.
 
I have 4.56's an AOD 3K stalled lockup and a Carb and I average 17-18 mpg highway roaring at 3000 rpms at 80 mph.

Maybe you need a lockup converter. Get that and the lentech strip terminator VB that doesnt lock up 3rd so only OD is a lockup "gear" and you should do much better.

That and pull some weight off the car (eases the load on the engine), get some underdrive pullies (eases load on the engine), an electric fan (eases engineload) and dont turn on the AC (better yet toss it altogether).

I used to get 25 mpg highway with carb and T5 and 3.73's and it only dropped to maybe 21 when I went AOD with the 3.73's
 
Step 1:
Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/article...c-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart .

Step 2: fix the codes

Step 3: Install a vacuum gauge so that it is visible while you drive. Try to keep it showing as much vacuum as possible while you have your foot on the pedal. You'll be suprized what your driving habits are like.
 
I second the "step 3"

I drove with a vacuum guage for a week up in maine and I actually hit 25 mpg once with 3.73's and a carb with a T-5. The AOD's will have more load on them but you can still benefit from a vacuum guage on any application.
 
jrichker said:
Step 3: Install a vacuum gauge so that it is visible while you drive. Try to keep it showing as much vacuum as possible while you have your foot on the pedal. You'll be suprized what your driving habits are like.
well i have a vac gauge (I am SD and like to monitor it). though i dont have a blower, it dips past 0" and into boost; at the same time, my foot is pushing hard enough on the gas pedal to flex the firewall. is this bad? :D J/K.

you are right, that is a nice way to ensure one does not drive too spiritedly.
 
Mine has what Volvo has labeled a "fuel economy" gauge complete with the little international symbol for fuel (pump w/handle). It's a great help to keeping you on the good side of the fuel economy equation, although on the highway the car seems to do just as well on the cruise control. And for many of the modded cars in here, the term 'fuel economy' is a bit of an oxymoron.
 
yeah i really dont have the money to change torque converters and valve bodys so thats out of the question...i was plannin on buyin a honda beater for the winter anyway, but was hopin that until then i could im prove my mileage.....thanks for all the replies