I get 15-16 mpg average regardless of highway or city. Where I'm at there's lot's of uphill grades that go on for as long as the eye can see.

I don't know if it's my motor being weak "last I checked I had about 140 psi compression in each cylinder so probably not" or if it's the 3.55's with 30's but cruising uphill on my way home at 45mph I shift the aw4 into 3rd and it sits at 2000rpm rather than lugging it at 1500 or so. Going up mountain passes I have to shift into 3rd as well or else I can't maintain highway speeds.

On level ground she remains peppy, but hills suck a little bit.

I'd still do the 30's and it's not so bad that I wouldn't consider 31's as far as driveability is concerned.