Bigger tires and lift affecting MPG...

[tommudd]

Before I installed the 265-75s I was getting 18 or so ( 265-70s/245-75s) , then with them on I went to 14-15 couldn't even use overdrive anymore unless I was on flat road and over 75 MPH. It would lug down so much, ran hotter etc
After the 4.10s went in went up to 20-21 on the open road and MUCH more useable power

 

[Ry' N Jen]

Before lifting our KJ got 24-26 mpg Highway.
After lift and tires, but before re-gearing it went down to around 18-20 mpg Highway.
After re-gearing it went back up to 22-23 mpg Highway.
That's all calculated with pen and paper with actual mileage driven, spread over many tanks
of fuel and then the average mpg taken.
Granted it all depends on how we drive and where we drive.

 

[osufans]

Good deal, that's what I was looking for. Unfortunately, we never drove my Jeep on long trips cause we had the van, so I don't have any estimate of what it gets truly highway on long drives. However, just average commute with mostly highway, I can't say I saw better than 19, maybe 20. Heck, even just doing a reset while driving to see what it averages during a specific stretch, I'd eventually level out at 21-22 (that's purely highway, constant speed, on cruise control.)

Compare that to those of you who were seeing a few ticks more before lift and tires, and are able to achieve close to the same after regearing, makes a bit more sense now.

So it appears that regearing after a lift and tires could get you back to your stock MPG. I'd be willing to concede that argument.