I have an 06 Liberty Sport. I have towed my 1450# 13 a few times with it, don't even notice it's there.
I have only towed my 17 @ what I am guessing is around 3k lbs, and it did great! It was less of a strain on the Libby than my 13/Element combo.
I like it as a car too, but the milage..
oh, mine is a 2wd with the 3.7, auto with class 3 hitch, stock tranny cooler, prodigy brake controller and soona WDH single arm. The Libby does squat a bit with the 17.
The libby has an astounding 5k tow rating when properly equipped.