60% diff in city vs. highway mileage ... ????
01-01-2007, 07:15 PM
#1
Thread Starter
Join Date: Oct 2006
Location:
Posts: 47
60% diff in city vs. highway mileage ... ????
Folks,
I've recently come back to V8s from imports (where I've been for the past 15 years or so), please excuse a stupid question. 2001 Mustang GT (recently purchased used for $10K, 86K on the clock), 25mpg on the highway, 8mpg city -- is this normal?
A few statements
(1) Its not a daily driver, gas mileage isn't the issue, the 60% difference is the issue
(2) Fuel consumption really bad on the way home from place of purchase
(3) I've done a full tune up since purchase (3 months ago, weekend I bought it); FCR unchanged since tuneup.
(4) Complete suspension (front and rear) rebuild (by me)
Steeda X2 ball joints, bumpsteer, alum 4 bolt caster/camber, rear arms (upper and lower)
FRPP front control arms
Bilsteins on all 4 corners
(5) Tires are worn to crap -- point is that I'm not ******* it around town, back tires break free when I sneeze loudly
(I know they need replacing, will do it after the engine rebuild -- it passed inspection, so its safe enough for now).
(6) No DTCs, all fuel trims, O2 sensors, coolant temp, et cetera in spec at hot idle and 30mph
(verified with AX5000, several capture runs reviewed with PC software)
(7) There are some indications on the underbody of a leaking rear diff seal (now or in the recent past),
but diff oil level is currently good and no spotting on my garage floor.
(8) I suspect that the last owner had some boltons on the vehicle; the exhausts are misaligned in the back,
and there is some left leftover engine dressing plus powder coated brakes (blue).
(9) Intake manifold has been replaced (by me) due to crack that the butt-wipes in Ford Warranty (corporate)
would not fix under the "extended agreement" due to the crack being about 2 inches from where they expected it.
Now running FRPP improved (alum coolant run) intake manifold --
verified all hoses and sensors properly connected (at least according to factory shop manual)
Anybody have any thoughts? Thanks in advance ...
[editted for typos]
I've recently come back to V8s from imports (where I've been for the past 15 years or so), please excuse a stupid question. 2001 Mustang GT (recently purchased used for $10K, 86K on the clock), 25mpg on the highway, 8mpg city -- is this normal?
A few statements
(1) Its not a daily driver, gas mileage isn't the issue, the 60% difference is the issue
(2) Fuel consumption really bad on the way home from place of purchase
(3) I've done a full tune up since purchase (3 months ago, weekend I bought it); FCR unchanged since tuneup.
(4) Complete suspension (front and rear) rebuild (by me)
Steeda X2 ball joints, bumpsteer, alum 4 bolt caster/camber, rear arms (upper and lower)
FRPP front control arms
Bilsteins on all 4 corners
(5) Tires are worn to crap -- point is that I'm not ******* it around town, back tires break free when I sneeze loudly
(I know they need replacing, will do it after the engine rebuild -- it passed inspection, so its safe enough for now).
(6) No DTCs, all fuel trims, O2 sensors, coolant temp, et cetera in spec at hot idle and 30mph
(verified with AX5000, several capture runs reviewed with PC software)
(7) There are some indications on the underbody of a leaking rear diff seal (now or in the recent past),
but diff oil level is currently good and no spotting on my garage floor.
(8) I suspect that the last owner had some boltons on the vehicle; the exhausts are misaligned in the back,
and there is some left leftover engine dressing plus powder coated brakes (blue).
(9) Intake manifold has been replaced (by me) due to crack that the butt-wipes in Ford Warranty (corporate)
would not fix under the "extended agreement" due to the crack being about 2 inches from where they expected it.
Now running FRPP improved (alum coolant run) intake manifold --
verified all hoses and sensors properly connected (at least according to factory shop manual)
Anybody have any thoughts? Thanks in advance ...
[editted for typos]
01-01-2007, 07:46 PM
#4
I ♥ Acer
Join Date: Feb 2005
Location:
Posts: 1,566
RE: 60% diff in city vs. highway mileage ... ????
ORIGINAL: draymer
oops, yes, you are correct -- [(24 - 8 ) / 24] * 100 = 66.6666666666666 %
question still stands
((whole - part ) / whole ) * 100
oops, yes, you are correct -- [(24 - 8 ) / 24] * 100 = 66.6666666666666 %
question still stands
((whole - part ) / whole ) * 100
01-01-2007, 07:48 PM
#5
Thread Starter
Join Date: Oct 2006
Location:
Posts: 47
RE: 60% diff in city vs. highway mileage ... ????
Mikev -- absolutely agree with you -- and that is the wisdom that I am looking for; I've never (25+ years of wrenching on cars in my garage) seen anything like this.
Sorry for not being more specific with my question.
Sorry for not being more specific with my question.
01-02-2007, 02:43 AM
#8
6th Gear Member
Join Date: Nov 2004
Location: Tennessee
Posts: 7,797
RE: 60% diff in city vs. highway mileage ... ????
Well coming from imports, you may need to learn how to get mpg out of a V8. I know driving my roomates WRX, I can shift at 4k, and it doesnt really doesnt boost hard, or accelerate fast. 4k in a V8 Stang is very high to be shifting at on the streets. You know what I mean?
01-03-2007, 01:28 PM
#9
Thread Starter
Join Date: Oct 2006
Location:
Posts: 47
RE: 60% diff in city vs. highway mileage ... ????
ZW99GT,
The comment is well taken and I believe you may have a big chunk answer -- I am shifting near the 4k mark et cetera. I did find an issue with the MAF yesterday and replaced that yesterday and mileage has come up, but its still low. Thanks -- I'll watch my shift points more closely and shift when what my instincts tell me is early.
Very salient point, thanks again!
The comment is well taken and I believe you may have a big chunk answer -- I am shifting near the 4k mark et cetera. I did find an issue with the MAF yesterday and replaced that yesterday and mileage has come up, but its still low. Thanks -- I'll watch my shift points more closely and shift when what my instincts tell me is early.
Very salient point, thanks again!