I have never checked my actual milage , I have a 2007 JKU "X", 3.8L, 6spd. But I took it on a 600 mile road trip last month to Central Oregon. Up over the Santiam Pass and into Redmond. Used about 3/4 tank, I drove around in the hills all day one day just wasting time, and we filled up before we left for home...Got home still had 1/4 tank or more.
So I think total miles was around 615, two tanks of gas, with a good 1/4 tank left.
I have 18" Sahara wheels on it, But I really can't complain about the milage for distance driven and playin in the hills like I was doing while over there..
Oil consumption....1/2 quart on that trip. Using 5W-30 Penzoil High Milage Vehicle oil.