Other than keepin my foot off the floor what can I do to increase my 8mpg??? 4.0 bored 20 over, auto, 3.55's and 33's is what I'm running and I just don't know what happened between Oklahoma and Oregon maybe just the terrain change but in Oklahoma I was gettin like 12-14 MPG city and now up here in Oregon I'm gettin like 7-9!!! So what are some cheap ways of getting maybe like 10 or 11??? I plan on regearing pretty soon and I'm not going back to stock tires!! Actually moving up to 38's when i regear but I wanna get a lil better mileage NOW if possible!!

try running it in 3rd on the highway... that will help highway mileage

Regear to 4:10's (not cheap, but it will help).
Tune up.
Take all unnecessary crap out of Jeep (weight = mpg).
Do you have a roof rack? If so, take it off (air drag).

how long has it been since you changed out your o2 sensor?



i just got back from moab, on 33's and 3.55's and got 14mpg. and thats with driving I-70 thru the rocky mountains 3/4 of the way.........at 80 mph with a strong headwind.

Buy a cheap econo box car....

Keep rpm's below 2000 when possible, I've noticed it helps.

When you go on long distance trips, run street tires, I know its blasphemy, but off road tires kill your mpg's.

Take off roof rack (or in my case, modify it to make it a little more aero dynamic)

Lastly, and as always, keep a light foot.

Go with narrower tires.
The wider the tire the more parasitic drag they impose and it gets even worse the faster you drive.

remove the fan clutch and put an electric fan clutch...

air up the tires

a thermostat that run a bit hotter...not the best idea but only if you drive this on the street

regear...


sell and buy a honda

x2 on o2 going out or the cat might be plugged. I dont see any other reason to go from 12-14 down to 8 mpg

Is there much of an altitude variance?



And +1 to putting a mast & sail on the roof.
Not sure if anyone suggested that yet, but it'd be damn cool.

Get a strong crosswind and you're set.

My jeep is relatively stock, but I went from 15.3 ish to 17.4 within one fill up. I removed my roof rack, washed and re-oiled my k&n and installed a new exhaust system.

does the K&N help with mileage? gonna get one when I get my new exhaust

I don't have a roof rack and I did a complete rebuild on the motor before I left Oklahoma!!! New head well new to me anyway, got it off the 87 motor when I put the 89 motor in my 87..... cleaned it up A LOT put new valve seals in it and cleaned the valves up with a wire wheel... new plugs and wires cleaned the TB new tps and iac new map sensor new air filter..... didn't change the o2 sensor cause it was clean but could that really effect my MPG???

yes the O2 plays the biggest part of how much fuel is dumped into your motor at a given throttle position.