I have Honda Pilot 2007 more than 300k I have being using high mileage conventional from last 100k now from last 30k I am using pennnzoil platinum high mileage 0w20 but now I have few regular full synthetic oil from valvoline full synthetic I bought from roses clearance 5 qt for $10.99 . My car has little oil leak but not major leak . Did going to regular full synthetic oil can make major leak because high mileage oil for years ?