I hear multi-faceted questions throughout the miscellaneous threads concerning the Liberty’s transmission fluid. The Mopar+4 (factory oil) is made from a Group III base oil but achieves Group IV performance. DCX designed this oil to be an extended 100,000 mile oil. Group III base oils are used in synthetic oils, but are not considered a super longevity oil. Whereas Amsoil is made from a Group IV stock oil that has been chemically engineered and tested for high performance and extended intervals. I would have to see a side by side comparison through multiple testing to prove that one is better than the other. Although, I would be nervous to take my Liberty to 100,000 miles running the factory oil. I challenge anyone (for your benefit) to take an oil analysis from the Mopar+4 at 25,000, 50,000, 75,000, and 100,000 miles and report the results. I think you might be surprised.
As a matter of fact, I will do an oil analysis at 15,000 miles just for kicks. 
An oil analysis is the only way you can really prove the quality or breakdown of the oil. However, quick observations are recommend and can be easily taken from the dip stick. For example, discoloration and foul odor are good indicators of a break down. An oil sample can be sent in for testing. Or taking your Liberty to a reputable transmission shop for a second opinion is advisable. Just because a vehicle goes 100,000 miles without having transmission problems does not mean the transmission oil hasn’t already failed 25,000 mile ago and has done permanent damage. Heat is what destroys transmissions. If the transmission fluid is broken down, heat build up will cause premature trany failure. For those of you who have a fair amount of miles on your transmissions, please give us a report on your findings. 