97 miles to tank ... bolt on GT?

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that is absolutely horrible gas mileage. just to give you some advice...let someone else who drives a mustang listen to your car, i thought my car was running really well until i pulled up to my work and some of my buddies who all own stangs were standing there and were like holy ***** your car is missing like crazy. turns out my number 3 cylinder wasnt firing at all because of a bad plug wire.
 
i don't have any bolt ons but i just installed a remanufactured longblock (5.0)... new ignition, new front O2 sensors... i've gone through 3/4 of my tank and i'm not even at 110mi.

do i have to do some highway driving for the computer to "re-learn" the new engine? i heard something like that.

i have heavy wheels and tires, but even with those my old engine gave me around 250mi/tank... never below 225mi even when i stomped it everywhere...

i'm about to take it to a local tune shop to see what they say. i'd still like to know if anyone has experienced this before. thanks.
 
D3l7a_3ch0 said:
i don't have any bolt ons but i just installed a remanufactured longblock (5.0)... new ignition, new front O2 sensors... i've gone through 3/4 of my tank and i'm not even at 110mi.

do i have to do some highway driving for the computer to "re-learn" the new engine? i heard something like that.

i have heavy wheels and tires, but even with those my old engine gave me around 250mi/tank... never below 225mi even when i stomped it everywhere...

i'm about to take it to a local tune shop to see what they say. i'd still like to know if anyone has experienced this before. thanks.
Holy HiJacking BatMan....
JK, man these things can go from bad on gas... to
 
How much are you putting in every time? (gallons) It seems you probably have other problems too but your fuel gauge could also be off some, i know mine says my tank is empty when i still have 5 gallons to go, so that could be one of the issues. It might be worth taking it to a dealer and let then do a checkup on it to see what's wrong so you know what you need to fix or replace, or just have them do it. That'd be what'd i do...

Good luck!
-Bart
 
that's similar to what i'm getting. w/ the old engine it was quick to drop to 1/2 tank (after 75 mi) and i'd miraculously get 150-175 mi w/ the second half of the gauge.

right now it's been at 1/4 tank for the last 25mi... just sorta stuck there. but i doubt it's gonna stay there for another 100 miles.

but thanks, i'll mention that to them. maybe they can check to see how much gas is actually still in the tank.

have you heard of the injectors being stuck open on these engines? i read something like that once but it didn't mention anything about what caused it and what the resulting gas mileage was like.
 
might want to check the wiring (have you actually computed the gas milage to rule gauge, etc out)? sorry if you said that and i missed it.

also make sure you dont have any leaks at the tank or along the fuel line run. gas loves to evaporate if given a chance.

BTW, i get 12 -15 MPG in town, for whatever that is worth.
good luck.
 
Sorry Madonionrs... cant offer any advice cause I'm in the same boat... I just got 110 miles on the last tank!! Car smells like it's running pretty rich, but that still seems a bit extreme. No leaks...
I thinking maybe missing a cylinder or 2 cause I recall my spark plugs looked like poop last time I had them off. Could they be causeing my problem??
 
I dont know if I'm the only one confused here or not, but I'll say it since I havent seen it yet. Fill it up all the way until the pump stops, reset the odometer, and drive until you get to 1/2 or 1/4 tank. Then fill it up until the pump stops again, preferably from the same station/pump, then see how many gallons it took and compare it to your odometer.'

Seriously, you cant get an accurate reading from any of the stock guages.

BTW, 21mpg average with mods in sig.
 
D3l7a_3ch0 said:
ah. today i let my gauge hit E. put in ten gallons and it's at 1/2. i know that's not right. tomorrow i'm gonna fill it up to see how many more gallons it takes. what's the tank capacity on a 95gt, anyway?
15.5 Gallons, if your really running that ****ty of gas mileage, check your o2 sensors, they could be all fouled up
 
65ShelbyClone said:
I dont know if I'm the only one confused here or not, but I'll say it since I havent seen it yet. Fill it up all the way until the pump stops, reset the odometer, and drive until you get to 1/2 or 1/4 tank. Then fill it up until the pump stops again, preferably from the same station/pump, then see how many gallons it took and compare it to your odometer.'

Seriously, you cant get an accurate reading from any of the stock guages.

BTW, 21mpg average with mods in sig.
i've heard you get better gas mileage on the i first half-tank than the last...not sure why, but if that's true, then comparing at half of a tank would be inconclusive; i'd fill it up, reset trip odo. and run as far as you an on it and then fill it up, see how many gallons you put in to fill it back and up compare that to the milegage on the trip odo...
 
hey isn't this interesting, i had a smog test done today for nevada registration... i passed. so right now i'm thinking it's the beat up suspension and heavy wheels. (i'm in the process of restoring the suspension)

the rear O2 sensors could be changed, i'll give that a try.

oh yah... i don't have mufflers yet they passed me. i think i've found a great shop and i'm stickin' with em... having them install 3.73's tomorrow(with the installation kit)... 100 bux labor. it's about time, too. those parts have been sitting in the box for a year.

whatever gas mileage i'm getting now, it's about to get worse. haha
 
TheUser said:
i've heard you get better gas mileage on the i first half-tank than the last...not sure why, but if that's true, then comparing at half of a tank would be inconclusive; i'd fill it up, reset trip odo. and run as far as you an on it and then fill it up, see how many gallons you put in to fill it back and up compare that to the milegage on the trip odo...

Thats not even remotely true and I dont see how it could be. If anything your economy would improve the farther down the tank you get due to less weight. That is, IF there was a difference, which there isnt.