Abnormal from my viewpoint. Should be ~13-18mpg city/highway. I typically get 16-19mpg rural / highway driving in the '08 GC Limited.
First, check your mpg the old-fashioned way: miles driven/gallons used. Mine compares favorably (95%+), but not exactly. Another 5.7L HEMI GC Limited owner told me that his system behaves the same way. This check at least establishes whether or not your electronics are performing properly.
You didn't state mileage or maintenance status, but spark plugs, air cleaner, and correct oil do a lot for HEMI mpg.
Champion 570 copper plugs ONLY for mine, every 30K miles. Verify this is the same for your model year. Apparently, these 5.7L HEMI's are very particular about spark plugs. Do not accept platinum "upgrades". Lots of bad stories by other forum members here. You can read more at XKJeeps.Com
and probably even download a pdf of your owners manual.
Other stories on this forum tell how dealers have incorrectly used 10W-30 oil in the HEMI. The MDS function works on 5W-30. If MDS isn't functioning, your mpg will drop drastically. Since I couldn't tell exactly what was used and my MDS was acting up, I changed fllter/oil myself to a K&N oil filter and Castrol Syntec (full synthetic) 5W-20 oil. It helped.
Final area to look at is the back side of the throttle body. Elsewhere on this forum, 90grandoneer
has helped us with the oil crud that builds up on the back side. There are even some before / after pictures by another Commander owner. Worthwhile endeavor. Use a mild
solvent to clean the crud, like alcohol. These intake throttle bodies are specifically listed by Chrysler as not being serviceable, yet we see stories that dealers will take >$160 to do a throttle body cleaning. IMHO, I wouldn't go for it.
If you do the work yourself, all of the above will cost you ~$75 in parts and 2-3 hrs labor. Be interested to hear about your results.