Hello everyone, wondered what you guys thought. I have a 2014 chevy silverado with a 5.3. Factory fill is dexos blend and first four oil changes are free. Called my service department and asked if i paid an upcharge could i go to mobil 1 full synthetic. He really seemed to want me to stay with the dexos. Did not recomend going full synthetic and warned me once i do switch i can't go back. What do you guys think?