I get like 10mpg.
Now that i'm broke it's a big concern... I've had lots of money lately and bought lots of stuff for my Jeep but now that I'm broke I need to get this fixed with the next paycheck.

I get 2200 RPMs at 45mph.
My overdrive isn't kicking in, no clue what that even is but all my friends that are mechanics told me that.
They told me it might be a sensor or something so...


What would make this happen?
I think this is the reason i'm getting **** gas milage.


I'm on 33x12.5s and a 4.5" lift, so I assumed i should atleast get 15mpg?

 

33s with stock gears will take your MPG down pretty good...

You need to get your trans figured out. Do you have a CEL on?

 

I get 7.13mpg so needless to say .I'm envious.Did you check the tranny fluid?Also check the shift linkage. You might have alot of crud on it and its keeping it from shifting.Just a suggestion.I had a Dodge that did something similar and it was dirty shift linkage.I wire brushed it and WD-40d the heck out of it and was fine for the rest of the time I had it.

 

33x12.50 on stock gears??? you're lucky to get 11mpg. ear down to 4.56 and your mpg should go up to about 15-16. i think your engine and tranny are having to work so hard that, your tranny can't even get to overdrive.

 

I have the same problem but I shift into overdrive and im stock but I do have enough black smoke to make my jeep look invisible

 

Whens the last time the oxygen sensors been changed?

 

"I get 7.13mpg"

Are you driving up hill, both ways to work?

 

I averaged 13 mpg on my last tank It was mostly street driving and im on 265/75r16 (about 31.5") with stock gears.

Is bigtires+stock gears worst on street or highway? (obviously street you get worst mpg) but does your mpg drop at the same rate on both street and highway or is one affected much more than the other?

 

everyone with bigger tires needs to realize with every rotation of the wheel you are moving faster or father that what your speedo or odometer is reading. unless you have re calibrated you gauges. For someone like the OP who is running 33x12.5 15 but your stock was lets say 215/75r15 Your gauges will be off by almost 20% so if your gettin say 10mpg, you're really gettin 12. Now I know some of you will say thats only 2mpg different, but when you get up to high speeds, like driving on the freeway. 20% is huge if your speedo says 65 you're really going 78. now the fact that your overdrive isn't kicking in could come into effect. changing gears would also help, your engine is workin overtime

sorry but it just drives me nuts when people say things like "I used to get 17 mpg but then I lifted (decreases aerodynamics) and increased tires (increases strain) and now I only get 14 mpg..." YOU ARE GETTING MORE THAN 14MPG... DO THE MATH. you can't expect to make mods to body/suspension and not see a difference in performance.... Just my 2 cents

didnt mean to hurt anyones feel goods by saying that

 

I have 31x10.50 on mine. The circumference of the new tires is 1.1 times that of the stock tires. I have to multiply what the speedometer and odometer say by 1.1 to get the correct reading since I haven't changed the gear at the speed sensor.

You're also having to use more power to turn those 33s from a start and their tread design certainly increases their roll resistance, and the lift makes your vehicle even less aerodynamic.

Down here, gasoline is $2.65 per gallon. If you're actually getting 11 mpg instead of 15 over the course of a year of 12,000 miles, you're spending over $770 dollars more per year.

Not shifting into overdrive and locking up the torque converter is a significant problem. Diagnose the problem and make the repair if you really want to save fuel. Remember, however, if have to overhaul the transmission and you gain 2 mpg, you'll have to drive it for six years to make up the cost. If it's a sensor, you may pay for the repair in as little as 6 months.

 

lol keep that to yourself if my wife sees that good bye jeep and yeah for prius
lol

 

Bravo, I could not have said it better myself.

 

I bought it with the lift and 31s, I don't know what he has done to it, but he was brazillian and hardly spoke english so didn't try to ask.

All I know is I drive like 80miles a day and gas sucks...
I guess i'll look into a few of the things said.

Thanks for the help

 

Wake up people. XJs were rated for what 16mpg when new on 215 or 225 tires. If you get anything within 2mpg of that number now your doing Good. If you lifted it or have oversized tires, on stock gears, you should be getting worse MPG. 2 ZJs and a XJ with 4.0 HO motor none have gotten better than 16 ever.
If you want to save gas get hybrid!!! Our Jeeps are ment to be enjoyed, have yet to see a high MPG vehicle, that gave this much, JOY.

 

Nope. I baby this thing. I was told to regear but it has lots of power so I dont know if I need to .It will light up the rears quick .I get almost 15 with the stock tires.Its even a low mileage XJ[82k original 96' year]