How cold does it get in your part of NC. I don't see any cold start problems for you even running 10w30 or 10w40. For that matter you might even be able to run 15w40 Durablend year round. Per MSDS sheets the 10w40 looks the best, closely followed by the 5w30. Also, Valvoline always tells me Durablend has 30% synthetic. It is Group III "synthetic."
