Each manufacture will vary. Over the years manufactures have become CHEAP! so many of these might not be in a Towing PKG... A higher amp hour rated alternator and battery. Generally a larger radiator, which translates into a better transmission cooling, If not a complete stand alone transmission cooler. Possibly an engine oil cooler, heavier or more correct terminology larger diameter front and rear sway bars, spring rates can be slightly higher allowing more weight carrying capacity. Possibly a different read gear ratio for increasing weight capability, a factory hitch might be available along with factory wiring harness for plug and play trailer lighting. CHECK with FIAT / JEEP for there list of Tow package features.
Search Jeep Liberty Questions
Jeep Liberty Experts