Im going to change the oil in my 09 Hyundai Genesis. The oil fill cap says 5w/20 and in the manual it says I can use 5/20 or 5/30. Im switching to Mobil 1 Synthetic. Car has 700 miles on it. Im getting a dry start chatter when the car has sat for awhile (at the dealer now for it). Dont really understand or know which oil I should use. I live in Delaware. I dont think it has ever gone below 0 here.