Ok so to start off, I am a competent mechanic. I am a heavy equipment mechanic/ fabricator by trade. I have built everything on this cherokee my self. Well lets start, 4.88 gears, 35 inch mtr's and 8.5 mpg. It got better mileage before the regear. I have replaced everything under hood to no avail, new exhaust system to. I have checked for closed loop, and yes it is going into closed loop. So basically, at the half tank mark I have went 77 miles
I have checked my mileage to a t with gps. Wth gives. I could of built a late 60's bronco with a small block, and get better mileage, and have a/c.

 

your driving a lifted box on 35in tires, and 4.88 gears, your gas mileage is pretty much where i would expect it to be. what kind of driving is it, is it city or highway/country roads?

 

7.7~ does sound way low even for a lifted jeep. not sure why though

 

Mostly around town and to the trails. I was getting 16.8 with 3.55 gears, and 33's before I bumped up. I literally put 20 bucks in run a few errands and its gone. And it runs like a top. Passes ca emissions also. If this is the mileage I'm going to get, its time for a ls1. But it should do better than that. Atleast 12 around town I would hope.

 

well i see you have a stroker, the stroker and 4.88s is a combo for bad gas mileage

 

manual or auto matic?

 

It is a auto. Ya the stroker was in with 3.55's and 33's. As a matter of fact i had 35's on for a few months before I regeared. It should do better than this. Its like driving a semi. Hell my 26000 pound mechanics truck does better. lol.

 

'eh that's what all of my Jeeps have gotten. I am suprised that mine is so bad. 35's with 4.56 gears. Wasted 35 bucks in gas in about 80 miles haha. My F-150 Supercrew gets almost double the MPG any of my Jeeps have got.

 

what kind of injectors are in there? pools of gas in the runners? are they stuck open? fpr has vacuum? cat plugged? dunno. that really sucks with the mileage. does it feel like it has enough power compared to before the stroke? maybe its a transmission issue...

 

have you thought about the torque converter of transmission work?

 

Chrysler gas gauges suck, I know mine jumps all over the place, fill it up all the way drive 100 miles then fill it back up so you know exactly how much gas you used

 

you should be getting better than that. friend of mine has a very similar set up to yours, 35s, 4.88s, stroker, and a whole bunch of added weight from armor and such. setting the cruise at 70 he pulls around 14 mpg while fully loaded, which is better mpg than he got with the stock motor, 4.88s, and 33s.

my guess is something else is making you run rich. either that or your fuel gauge is off. when did you last replaced your oxygen sensor?

 

i go round trip to work 55 mi takes 16$ in my f250 diesel, i put 20 in the other day and was lower then when i started , in the jeep, 35's and such,

 

Message me if you figure out your problem, please. I get the same you get and I have a smaller lift and smaller tires.

 

put 38s on it 35s to small for 488s lmop