bad gas mileage....

im lucky to get 200 miles to a tank... half highway, half city driving. ive never been one to complain about gas mileage... but 10 miles a gallon seems a bit low. ive just replaced the plugs/wires with no imporvment... I live in phoenix, along with the daytime temps being 110+ they also use different blends of gasoline in the summer. I know hot temps means bad mileage.. but this seems worse then it should be. any suggestions?
98 cherokee, 90k, 4x4, 4.0, auto trans, 31x11.5, 3 inch lift

See if you can get a good scan tool (not from AutoZone) on there and make sure the O2 sensor, MAP, ECTS, etc are all funtcioning properly. Other than that, there's not much you can do...put a brick under the gas pedal.

What kind of plugs did you use? I also think that the lift and 31" tires aren't helping you out that much either. I changed my '94 from 225's to 235's and I cannot get more than 300 miles to a tank-in fact, the best mileage I have gotten was 22mpg. I have been doing some experimenting with speed and driving habits and yes I too should be getting better. I tuned it up, fuel filter and the whole deal and even kept up on the tire pressure and still cannot get better than about 18-19, and most of my driving is highway. The tire size may play a role in this on mine, but I think it will definately affect the mileage of yours. Keep us posted as to what happens. Thanks

Jeff

I use Champin plugs, and tire pressure is as recommended, not sure what else to do

Find someone who carried BG's 44K fuel injection cleaner. It's kick ass stuff!

BG 44K

http://www.rynoproducts.com/8.html

remember if you have not changed your seedo gear that you are going about 10% further then what the Odometer reads. 200 mile = about 220. You have the same set up I have and I get around the same MPG. I would also recomend a good tune up as well as a new O2 sensor. The maintenance schedule says to change the o2 sensor at 82500 miles or 82 months. I have one in the garage just need time to put it in. Will let you know if it helps.

On the BG44K, check into seeing if there are palces in your area that sell just the can. I found that the texaco quickie lube place sold it in the entire fuel system package that cost $80, and to get them to open the package and sell me just the can, they still wanted to chargeme $40. I then found a Mazda dealership in my town that sells just the cans and for the same price as listed on the internet, $20.