Hello, looking for some help troubleshooting high fuel consumption in my 03 Gas Liberty. Im getting about 15 mpg on the highway and 12 in the city. I’m running 245/75/16 tires on moab rims, regeared to 4.11. In my attempts to troubleshoot this problem I’ve replaced spark plugs (NGK copper), they came with 0.44” gap, I didn’t bother adjusting to 0.40” because I figured 0.04” can’t make a measurable difference. Ignition coils got replaced, all four o2 sensors and cleaned MAP sensor, and still getting terrible mileage. My belt tensioner ran out of grease and started squeaking, it didn’t have any play in it so i repacked with grease and put it back. So if anyone has any suggestions what else i can try i would appreciate that.
High fuel consumption
- Thread starter vlad588
- Start date
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Luke
Interloper
How’s your PCV looking?
Aceofspades
Full Access Member
Seems normal for mine , 02 and 03 , to reach about 280 miles and the gas light will come on…
Yeah that about 20 mpg which what i would love to get but for some reason I’m sitting really far from that
When was the last time the brakes were done? Could you have a sticking caliper creating drag?
Yeah thats a possibility, I’ve done them couple years ago, i drove around a d checked the brakes, both rear brakes were hotter then front but not super hot. But that’s definitely an area i’ll need to look at.
jeeptorino68
Full Access Member
I have the same setup and get the same mileage in my 2002. I often wonder about the calipers too or the wheel bearings. Ive replaced both, but on flat ground in the driveway or garage the jeep is incredibly difficult to even push by hand.
When replacing the wheel bearings the axle nut torque spec seemed very high...perhaps ita too tight and binding the wheel bearings???
When replacing the wheel bearings the axle nut torque spec seemed very high...perhaps ita too tight and binding the wheel bearings???
Aceofspades
Full Access Member
I feel horrible for commenting on this and not proof reading.
Replace the 2 with a 1
On road trips where I only stop for gas , I got a high as 270s once
Yes I run both stock rims with cooper AT/4 and the Moab wheels with 265/75/16 10 ply etc
Doesn’t seem to matter. And the 03 is my baseline as it’s driven by my wife. So yea. Not sure. Maybe when they were brand new ?
Looking at the fuel economy of 2022s the v8s and even the v6s don’t seem far off from each other. Makes you wonder why have a 6 these days when the 8s are getting the same
turblediesel
memberable
14-19 mpg. Still waiting for Hurricane Katrina diesel prices to come down.
turblediesel
memberable
Must be nice. Mine got 19-23 until the required dealer F37 reflash. Your fuel is considerably cleaner and better than what's available in the US. That, and the differences between US and export models make the difference.
WheelNut
Full Access Member
A US gallon is 3.8L and a UK gallon is 4.4L. That's a big difference when looking at MPG.
I'm getting about 12-14mpg in the city. Keeping your foot out of it can make a 10-20% difference in fuel economy. If you live somewhere with really heinous traffic like I do getting mileage like you see from people on fuelly.com is nearly impossible. The KJ is rated at 15mpg for city, so you are 20% off the baseline rating. My 05 runs pretty well and it has fresh plugs, coils, injectors, PCV, air filter, and a clean MAP sensor. None of that made any difference to the mileage as far as I can tell. Over sized all terrain tires will use more fuel, but there is no point in having a Jeep with factory sized highway 'eco' tires, so not much you can really do.
Edit: I see your in Vancouver too! I don't think there is much we can do here haha. The traffic is so slow. Oh well, the ol' KJ is still cheaper to run than a new Wrangler 4xe with a payment of $1000/mo.
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Yeah Vancouver traffic is dead slow, it just sounds like some guys here are getting 20 mpgs or so, which would be fantastic. But yeah after replacing everything and still sitting at 15 mpg im ready to give up and accept my fate and mount a jerry can on my tailgate.
Deb'nKJ
Full Access Member
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I was surprised, & a little disappointed, that Jeep didn't seem to improve on the XJ 4.0 (indeed my 4.7 WJ was marginally better than both) but it is what it is. No point in spending loads on stuff to improve mileage 'til you are confident you will ever be able to recoup the cost in using less fuel. Without doing the maths, I would think any improvement under, say, 7 mpg is not worth chasing (ymmv - how very appropos)
WheelNut
Full Access Member
The XJ was 700Lbs lighter than the KJ, so that probably is what did it. Couple that with the fact that Jeep didn't move to a 5 or 6 speed auto transmission, plus they didn't add any advanced engine technologies like variable valve timing or variable intakes, etc to the engines it is no surprise that there was no improvement in fuel economy.
Rant Mode:
I wish I would have somehow been able to have purchased a 4 cylinder but they are super rare. That would have helped the mileage in an appreciable way. The extra power isn't really necessary for what I do with my Jeep. I rarely get the chance to break 110kmh (70mph) in it. Or if I could have found a decent KJ with a six speed manual that would surely do better than the old fashioned 4 speed auto. I hate the 4 speed! Worst part of the KJ IMO.
If someone could figure out a kit to K-swap the KJ along with a ZF 8-speed that would be ideal! Hahaha
:Rant Mode End
Rant Mode:
I wish I would have somehow been able to have purchased a 4 cylinder but they are super rare. That would have helped the mileage in an appreciable way. The extra power isn't really necessary for what I do with my Jeep. I rarely get the chance to break 110kmh (70mph) in it. Or if I could have found a decent KJ with a six speed manual that would surely do better than the old fashioned 4 speed auto. I hate the 4 speed! Worst part of the KJ IMO.
If someone could figure out a kit to K-swap the KJ along with a ZF 8-speed that would be ideal! Hahaha
:Rant Mode End
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