I use 5w30 Mobil 1. I change twice a year. I just pulled the pan to do the gasket and there isn't a single metal filing in the pan and I drive my car pretty hard. I say go to synthetic if you are going to use the car the way its intended with the boost gauge at max most of the time. If you are going to change it regularly and drive it like a little old lady then stay with conventional oil. That's my just my opinion.