Miles per gallon?

I had them replaced 20k miles ago when I had an oil change done. I didn't trust that shop and thought maybe they were gapped wrong. But at 200k+ miles I figured I'd get a compression check and new plugs at a place I trust. To quote the shop new shop who I asked for a compression check at "two of the spark plugs crush washers weren't crushed". Then they said bring it back if new plugs installed right doesn't fix the loss of power issue and then they'll do the compression check.
That's what I get for trying to save time by paying for something I could do myself. Before that it was at least 50k.

I got a distinct feeling from that first shop that they didn't like Jeep's.
You pay someone to replace your spark plugs? LOL wow...
 
2005, 6 speed, 108k, stock 4.0L, 32 inch tires, 3.73 gears, new exhaust (3 cats, 4 O2 sensors, no CEL’s ever), new fuel pump, new spark plugs. With 90% City\10% Highway, I consistently get between 14.5-15mpg. Pretty much exactly what the Moroney sticker says and what fueleconomy.gov predicts for City driving. I would love to see what I would get with highway driving, but since I didn’t buy the TJ for taking long trips, I doubt this test will be happening any time soon. I take our more comfortable JK on long trips and still get crappy mileage numbers, LOL.

P.S. if you have larger tires and didn’t correct your speedo, your odometer won’t be accurate, and your calculations will be off (i.e. your real mpg will be higher than calculated, unless you compensate for the tire size difference in the calculation). Just wanted to throw that out there since some forget about this, especially if they bought a Jeep with larger tires and never checked to see of the speedo was “healed”.
 
You shouldn’t own An old Jeep if you’re not even willing to replace your own spark plugs ...just saying
I do most of my own installs given I have the right tools. But basic maintenance like oil changes are in the category of time better spent on other projects. If I'm leaving it for half a day, drop off, work, pickup. Why not have them change plugs too? Easy enough and saves my weekend time for much more fun projects. And hey, there's a reason I'm not posting about all the Gremlins I have to hunt down 😉. Do things slow and know when you're in over your head. Pay someone to do the messy work you don't want to.

If youve got the money to pay someone to do it why not own a jeep?
Pay someone to do the boring stuff so you can do the fun stuff.
 
I'm about 12mpg w/ 33s and 3.73 gears from a 5sp. I expect it will improve when I regear.

Edit: Forgot to add that my O2 sensors were replaced last year and my fuel trim numbers are where they should be.
Same setup... 12.5 mpg with 3.25" lift.
 
I've never checked mine and probably don't want to either.
Although on my '16 4-Runner, I average 14-16. And while towing a 6x10 cargo trailer, it's 11-14.
And the Moho with a 496 BBC, is 8-11. At its worst was 5 against the wind across the CA. & NV. desert while dragging the Jeep.
 
That’s a toxic attitude. We don’t put others down for not being mechanically inclined on here.

For real, even if one IS mechanically inclined there's nothing wrong with farming it out. My old roll-away is in the garage filled with enough tools to do a complete frame-off, but I put my wife's SUV in the shop for brake pads last week because I'd rather have time for other priorities like taking my kids to hockey practice. Who cares?