Topic: Gas Mileage Thread

[TrailsLessTaken]

it could be but im not gettin a check engine light coming on and when i hook the computer up to it, i dont get any codes to pop up on it. i'll go buy a new one this weekend and see what that does

[somthinwicked]

15 mpg mostly, 1998 2.5L SE. 31/10.5 tires/wheels, Engine Light On, getting it looked at asap.

[Mozman68]

13.5 with the new gears.....and new weight. Not as bad as I thought it would be, but I was hoping for 15. Tracking another tank full to see if I get the same.

[Jeffy]

13.5 with the new gears.....and new weight. Not as bad as I thought it would be, but I was hoping for 15. Tracking another tank full to see if I get the same.

I bet it's the gearing. 

[Tsd]

I got 16, everything stock, fat driver and busted o2 sensor 

[dexetr30]

I was getting around 15 mpg. A month or so I bored out the intake manifold to match the bore size of the 4.0l t.b. and installed a Taurus fan. As the weeks went on I noticed crisper throttle response and better overall power. I guess I had to let the ecm catch up with the intake mod? Anyway... I'm hitting an average of 18 mpg now. My catalytic converter is starting to smell a bit and it's time to change the o2 sensor. Things may improve after I do these two things also.

[Mozman68]

update.....14.3 and 14.7 on my next two fill-ups respectively.

And then the next one earlier this week.....15.3. 

Gonna keep tracking until I end up with a good average.

[bidi]

I'm amazed how bad mileage you guys are getting.  I've always gotten 20mpg average, sometime it would hit 18mpg, but that's the lowest it's ever been.  This is with 31" and 2" lift.  I generally travel in fairly flat roads, but it's pretty windy where I live now... that accounts for the 18mpg.  I've actually been thinking of getting a DD, but not sure since I don't take the Jeep out anymore I wouldn't have a reason to keep it anymore.

[Mozman68]

I'm amazed how bad mileage you guys are getting.  I've always gotten 20mpg average, sometime it would hit 18mpg, but that's the lowest it's ever been.  This is with 31" and 2" lift.  I generally travel in fairly flat roads, but it's pretty windy where I live now... that accounts for the 18mpg.  I've actually been thinking of getting a DD, but not sure since I don't take the Jeep out anymore I wouldn't have a reason to keep it anymore.

..and this is GPS certified?? Or, you've changed your speedo gear??

I dipped back down into the 14's with my last fill up...I'll take 14.5 as a great average any day with my setup!!

[bidi]

I changed the speedogear.  It's also been calibrated since then though.  My fuel pump short circuited on the trail about a year ago (cost me $800, too... bastards) and they went ahead and calibrated everything.  Mileage increased after the new fuel pump by about 1-2 mpgs.

On that note, with the original speedo gear and larger tires you'd actually seem to get lower mpg since you're moving more than your odometer is registering (your odometer would say you traveled 100 miles instead of 110, for example, so you'd be short 10%).

[Mozman68]

On that note, with the original speedo gear and larger tires you'd actually seem to get lower mpg since you're moving more than your odometer is registering (your odometer would say you traveled 100 miles instead of 110, for example, so you'd be short 10%).

I was short when I ran the 31's....but I don't have a speedo gear anymore....I'm electronic now, so running about 10% MORE...using the GPS as a speedo for now and also to make sure I am using accurate mileage numbers.

Too cheap to spend the hundred bucks for the electronic module....can't even remember what it's called.  The guys who did the work on my rig thought I had one for some reason.

[Jeffy]

I was short when I ran the 31's....but I don't have a speedo gear anymore....I'm electronic now, so running about 10% MORE...using the GPS as a speedo for now and also to make sure I am using accurate mileage numbers.

Too cheap to spend the hundred bucks for the electronic module....can't even remember what it's called.  The guys who did the work on my rig thought I had one for some reason.

The Dealer can actually calibrate that for you.  Otherwise, you can get a Jet or Dakota or Superlift module...

[JamesPadgett]

according to my uncalibrated speedo i am getting 13mpg.
Transmision Type  AX-5
Engine Type AMC 2.5L TBI
Tire Size 33/ 10.5/ 15
Differential Gearing 4.88
Speedometer Calibration n
List of ENGINE Mods: ported throttle body, throttle body spacer, k&n

I am planning a sm420 /dana300 swap so i am thinking when i do that i will fig out my speedo.

[aw12345]

went from 33/12.5 tires to goodyear mtr 32/11.5 both sets of tires are the same diameter milage for short trips went from 15 to 17 mpg am quite happy about that

[whitejeep94]

I have a 94 and run 31 with 4.10 /my upgrades are cut the airbox with k&N and knew header  and flowmaster 40 series airaid spacer and i still only get 10 mpgs

 what can i do to get my mpgs up ?