That's right at what to expect if your 05 4.0 auto is pretty stock. In fact, 14 was the govt combined rating for that rig when it was new:
https://www.fueleconomy.gov/feg/bymodel/2005_Jeep_Wrangler.shtml
As has been said, a TJ has the aerodynamics of a brick. Also, drivetrain HP loss vs HP rated at the crank is on the order of 30%, dyno proven for mine and others like @Jezza. These vehicles have many worthy attributes, but fuel efficiency is NOT one of them.
I was looking at my window sticker an hour ago, 2006 LJ
