I plan on buy a Jeep grand Cherekee with the 5.7 liter Hemi engine.The only oil that must be used is 5W20.I'm thinking of using Mobil Clean 5000 for 3000 mile oil/filter changes then switch to Mobil 1 with 5,000 mile oil/filter changes.I want to break the engine in correctly.Any thoughts would be great.Thanks Joe