They don't make the Liberty anymore.
The 3.6 V6 has plenty of power.
In the Wrangler it's rated at 285 hp. I belive slightly higher in the Ram. 290 hp in the GC.
Many of the older V8 workhorse motors used for towing had less HP.
In my Wrangler I've towed about 1,500 lbs without hardly noticing it.