I agree w/ scuba, IMO Thinner tires and bigger wheels is only for Exotic Big Cars like a Navigator or an X5. For this type off road 4x4 type of car, thicker ( on the sidewall ) tires and smaller wheels looks better and more aggressive.
I dont see the lifting nice either and as for the mileage, it is posible that it really has that mileage given the year of the car, but a '99 maybe not.