Yeah I feel your pain man, many do, they are Jeep after all haha. For me I think the suspension killed mine id have to say, the huge drop and the heavier brakes/wheels along with the way i drive, I'm lucky to get 10mpg and I'm driving the v6 haha. People dont realize every mod they make may effect their MPGs and usually its for the worse haha.
Id figure the suspension mods would help but physics experts have explained to me the way it works and the geometry now makes for a guzzler, the heavy rotating mass from brembos and 20" wheels don't help much either.
I must say at best I can get 14-15mpgs but I drive like . . . well a 21 year old with somewhere to be haha, so 9-10 it is haha and I roll on and keep the wallet full