walkerja191
NAXJA Forum User
- Location
- Rochester, NY
I have a '94 Cherokee sport 4.0 with a 4 inch lift. I have tiny tires on it right now for the winter and I am only getting 13 mpg. Does anyone have any idea what could cause this?
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Why is my gas mileage so bad
- Thread starter walkerja191
- Start date
MnGrnXJ
NAXJA Forum User
- Location
- Toccoa, GA
Thats some crappy gas mileage... Check your air filter, plugs, wires and coil. I just did a tune up on my 96 XJ and replaced all of 'em and I am getting 20 on the highway and 17 in city. Of course my Jeep is totally stock at the moment so that prolly makes a bit of a difference.
oh yea, when was the last time you changed your o2 sensors?
oh yea, when was the last time you changed your o2 sensors?
igotanxj
NAXJA Forum User
- Location
- Citrus heights
X2
My 96 gets 20mpg on the highway with 2" boost and 29s. Check all the above mentioned stuff expecially your upstream O2. If it's original- replace it. A lifted XJ will get worse mileage, but I don't think it should get that bad. Also, what is "tiny" tires?
winterbeater
NAXJA Forum User
- Location
- Royal Oak, Michigan
13 MPG on short trips around town in the winter and warming it up a little would be totally normal.
igotanxj
NAXJA Forum User
- Location
- Citrus heights
Thats true, if you do a lot of around town driving, and lots of short trips where the engine is basically just trying to warm up the whole time, then 13mpg would be normal. Highway is a different story tho.
winterbeater
NAXJA Forum User
- Location
- Royal Oak, Michigan
Just tested my stock 2000. Slightly disapointed at 18 MPG at sustained (3 hour) 80MPH drive. I expected about 20. I did have a 5 or 10 minute warm-up included in that though, but I think that's just an excuse. This vehicle is new to me and I probably need to test the O2 sensors. Should bad O2's show up with a code reader?
Jeepm@n
NAXJA Forum User
- Location
- Northern, WI
I just read in OEM tech that a gentleman had a loose connection on his temp sensor causing his Jeep to stay in open loop mode. Not allowing the engine to use the O2 sensor to adjust air fuel ratio. My 96 and my 94 average around 17-18 in the winter months. All backroads and 30% 4wd use.
I've noticed a drop in fuel mileage in all three of my vehicles, '07 Buick Terraza, '06 Chevy Van1500, and '92 XJ
Here in Florida it's been attributed to E-10 being added at the pump:
http://www.floridajeepers.net/viewtopic.php?t=50961&highlight=ethanol
If you read through the entire thread some have noticed as much as 23% loss in power as well as a loss in mpg!
Here in Florida it's been attributed to E-10 being added at the pump:
http://www.floridajeepers.net/viewtopic.php?t=50961&highlight=ethanol
If you read through the entire thread some have noticed as much as 23% loss in power as well as a loss in mpg!
igotanxj
NAXJA Forum User
- Location
- Citrus heights
I would say that's because of the 80mph speed. Slow down to 60-65mph (i know, it sucks) and you'll get your fuel economy back. XJ's have the aerodynamics of a brick. If your O2 sensors were bad you'd be getting closer to 10-13mpg. Usually, they don't show up with a code, but if you can read live data, a bad O2 sensor might read lean.
xcm
NAXJA Forum User
- Location
- Southern Oregon
i dunno about HO's, but on a renix, a missing, or wrong thermostat will have the same effect. if you havent been into the cooling system, this is a high probability on 15+ year old cars bought for cheap. i have found at least 3 xj's were missing the tstat while working on them.
when was last tune-up?.
o2 change?
cat-change? could be plugged
I agree.
18mpg at 80mph is pretty good..
winter - no need to test the O2 sensor based on the mpg at that speed.
E
Hammered
NAXJA Forum User
- Location
- Jeep Fiend Club
keep in mind youre driving cinder block on wheels. Heres what I got, not sure if you want to throw money at this stuff.
http://www.performancedistributors.com/jeep.htm
Mtb Jak
NAXJA Forum User
- Location
- Seattle WA
winter gas effects it too..
- Location
- Cheyenne, Wyoming
i have a 98 with 5" of lift 31" tires 4:10 gears and im getting 21 mpg!
Last edited:
igotanxj
NAXJA Forum User
- Location
- Citrus heights
^luckyyyyyyyyy
- Location
- Cheyenne, Wyoming
and i drive like i stole the thing! haha i was getting 16 previosly with stock gears...
My 2000 4.0 AW4 3.5 RE & 31's ~ 18mpg in mixed driving with AT's and now that winter is here I get ~ 16-17 mpg with MT's. Check you operating temp...mine sucks down gas like a fat kid at a pie-eating contest if the temp is too cold. I tried a 180 stat after I added a winch and my mileage dropped to 12mpg...changed the stat back to 195 and never had another problem.
vortex
NAXJA Forum User
- Location
- Chehalis, Wa
Wow i get like 8 to the gallon.....of course i have a 3" budget and 32's with 3.55's. soon to have 4.10's
-PJ-
-PJ-
XJFever
NAXJA Forum User
- Location
- Anchorage, Alaska
what were you getting before the gear change? I have a 99 with 4.5" of lift 31" tires and stock 3.55 gears. I'm getting about 12 in town in 2wd on the warmer days of the years.
On another note does anyone know if the heater or electric fan in the winter will decrease gas mileage? I'm thinking about just unplugging my electric fan because its so damn cold. Someone told me that using your heater doesn't use any extra gas because it just draws the excess heat your engine is producing instead of wasting it.
