My question is Will there be any problems changing from regular 5w-30 to 5w-30 full synthetic oil? It seems that they are going to stop producing regular oil. I have been using Pennzoil 5w-30 in my 2013 Durango Crew since new. It has the 3.6 v6 with 126k miles on it. When I change over to synthetic what will my oil change interval be? Do I go by miles or engine hours?