My jeep has been getting poor milage lately. seems as if it was since having all my fluids changed. also, been getting a little hum from the rear end I think, as well as a clunk when I accellerate from a stop in the rear? could all this be a compound problem?

my tires are wore extremely bad as well. I have changed my plugs about 20k ago, ran fuel system cleaner through, and so on.

 

Tires worn? Could be alignment?

 

Would help to know such data as:
- JK year/engine, (3.8 or 3.6), total miles to date
- Manual or auto tranny, two or four door, engine mods - Cold air intake or cat back free flow muffler
- Mods such as lift size, wheel/tire size and type - A/Ts, rock crawlers or mudders
- Ring and pinion ratio
- Added heavy weigh mods such as steel bumpers, winch, roof rack, etc
- How much of a load do you carry, tools, parts, survival gear, etc on a routine basis?
- Average MPG you have recorded to date. How much of a drop have you observed? Over what period?
This data will provide us with a point of departure to make comments and offer possible solutions.

 

He looks to have a 2011 JKU automatic with leveling kit and 33 S/T's. With stock bumpers unless profile has changed. Kojak what gears are you equipped with and what kinda mpg are you getting? Are you basing mpg on computer?

 

Got r buddy. I'm working on some bumpers and things but that is how she sits now. 3.73 gears.

Using the dash plus how frequent I visit the gas station. Around town it 17 plus liters per 100km. Where it used to be 15 or less. Have seen up past 20.

 

They use ethanol in your parts,

 

Isn't that around 13 mph? I have a 2 dr 2011 automatic with 3.73 gears and 32" tires getting around 17 mpg.

 

2009 3.8L auto/3.73 35s bumpers and rails and I'm about 18L/100km / 13 mpg
I towed my enclosed 8x10 trailer hauling a motorcycle back and fourth to Albany and saw 23-24L/100/km / 9-10 mpg. That was fun

last option for me is to regear and see if that helps even the slightest. A JK is definitely not for those on a budget

 

Curious, with the larger tires did you try a programmer?

 

3.8/35s/auto/3.73 needs 5.13 or 5.38. Must be a bitch to drive. My 2009 with a six speed/4.10 and 33s was a slug.