Gas milage?

What is everyone else getting I just took my first long trip with the 33" mtr's and the 4.5 re lift with 3.55 gears running a true 80/85 in third on the aw4 I was able to get 13mpg turning 3000 rpm in fourth letting it shift its self it was more like 12.5 over a 600plus mile trip. Is this just because of my need for speed and the awesome fridge like shape or would gears actually help?

A set of 4.56's in place of the 3.55's will definitely help gas mileage and performance. Your engine has to work too hard to pull your Jeep in 3rd gear and overdrive because the gearing has become ridiculously tall with the 33" tires.
I have stock 3.07 gears, 27.4" tires, AX15 5-speed tranny, and get 20mpg cruising at 80-85mph in 5th gear.

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Modified 1992 4.0 XJ Laredo UpCountry, 169k miles, AX15, NP231, D35c rear, D30 front
Estimated 240hp@5250rpm/280lbft@3500-4000rpm
1/[email protected], race weight 3490lb
Future mods: 4.6L stroker
Website: Jeep 4.0 performance
Webpages: Electric fan, IAT sensor relocation, Intake manifold heatshield, Oil temp. gauge install, Jeep 4.0 cam specs, Jeep engine dyno graphs, Automotive formulae, CTS resistor trick, MAP adjuster

I usually get 15 MPG highway with my AW4, stock gears, and 31's running 70-75 in OD (4th)

When I installed the 33" tires, my gas mileage fell to 12 mpg! When I installed the 4.88's, it picked back up to 18 mpg (using the A/C most of the time too) and the performance difference is amazing. Also, the trans is taking a beating from the overgear...at the very least install a cooler or the trans could end up toast.

I've been getting 17 with 30's and a budget 3" lift in back 1&1/2 in front.

You must also take into consideration the speedo gear, unless you are getting your odo readings from a GPS.

When I regeared, my milage went through the roof! arty: But my speedo went from being off in one direction (telling my my milage was sucking by registering too slow from the tire change) to off in the other direction (telling I was going way too fast from the gear change). I knew most of this ahead of time, cause I was checking all this on my GPS.

I've installed the proper speedo gear and now my milage is just OK. 15-16mph on average...

bburge

I used my girl friends car with stock tires as a reference for the milage and speed because she followed me.