I don't know as far as price but things like the oil and weight you choose sometimes effect things like that. Are you confident the correct lube is in there? My SRT tapped when I brought it home from the dealership where I bought it. They just performed service that included an oil change. I wanted to make sure the right oil was in the car so I changed it myself after I had it about two weeks. It went away and never returned in two years. Not saying this is a cure for mechanical issues but it is a simple thing that some overlook. The tolerences in these motors are very close thus my car calling for 0W40.