View Full Version : extremely poor gas milage

06-21-2016, 05:24 PM
Guys, I own a 2005 Jeep LJ Unlimited , 4 litre, auto, 31" mickey thompson deegans on it. 3:73 gears. Mileage is 170,000 KM. I know jeeps are hard on gas, but i get like 200 KM. to a tank in city, 300 on highway. My 2004 TJ gets close to 400 city, same motors, I am wondering why the lj is so bad on fuel. For some reason, it feels like its not loose and doesnt roll easy. which might be something causing bad mileage. It also seems like it's starving for fuel when idling. Changed plugs, wires, air filter, still no change. What else can I change or do to get a little more gas mileage? I try to keep it under 2000 rpms, as i heard it helps. Any suggestions? Throttle body? vaccum leaks? egr valve? TPS? 02 sensor,upstream? Use higher octane gas then regular? Any suggestions would be nice, thanks for the replys in advance. I need some direction, as dealership would cost me thousands with no answers.

Lucky j
06-22-2016, 10:52 PM
Wow, mine is not that good either, but I run 33" with the 3,73 but manual 6 speed.

Are you sure that as you say, it does not drag anything, like bad bearing, brakes? Engine, air filter? Did you chech it for cleaneness, a bird nest, etc.

Changing gas for hogher octane will not change anything.

Btw, I get 350 km with a trailer, and She run on the heavy side with front and rear winch, heavy rear bumper and recovery gear, and my self, a heavy boy.

06-23-2016, 01:39 PM
Hi J, thanks for the post, I will check the bearings and brakes this weekend, it's fairly clean, no nests, it just doesn't roll like my tj. but thats a good start. thanks again.

06-23-2016, 07:45 PM
hey Lucky j, won't wheel bearings make a lot of noise if shot?

06-23-2016, 11:22 PM
Mine gets 12-18 mpg(not sure on KM translation). It is an '04 Autotrans, factory gears on 35 BFG TA KM2's.
I have to do some work, just ordered a Griffin Rad/shroud/fan, new water pump made for higher volume at idle and 20% more at speed, plus a few other goodies($1200 worth). Wife was ok with it, I ordered her grab handles for the roll bar, for easier entry, she's taller than I am, but spoiled.

The old guy

Lucky j
06-26-2016, 10:55 AM
hey Lucky j, won't wheel bearings make a lot of noise if shot?

Yep they should, but have to start somewhere. On my other suv, I do not notice until I check them out.

Forgot, I know you are talking of total distance, but how much liters are you talk ig about. I know that out of a 75 litres fuel thank, I'm only able tu use about 60 to 65. That reduce autonomy big time.

06-27-2016, 01:40 PM
Hey Lucky J, yes it's true about the fuel tank, when the light comes on warning me low fuel, and I fill up it only takes 50 ltr's. so 22 ltrs is never used, reducing it to a 50 litre tank. for the mileage. Therefore my calculations should be based on 50 ltrs. Haven't checked out the bearing yet, been busy with work too much. thanks for the reply. will keep you posted.