Maybe in later model years, but the owners manual for my 2006 does not specifically recommend "synthetic" oil. It states, "If you chose to use such a product, use only those oils that are API Certified and meet the SAE viscosity standard. Follow the service schedule that describes your driving type."This is false. Chrysler has been recommending full synthetic for all 3G Hemi V8 engines for several years..
From page 485:
5.7L Engine Oil - Use SAE 5W-20, API Certified, meeting material standard MS-6395