In our daily drivers I change the oil every 6 months (spring and fall) regardless of mileage. That's usually between 5,500 and 7,000 miles on each, but on occasion it's been closer to 7,500 miles.
I use whatever brand name conventional is on sale at the time I'm ready to change the oil.
I use whatever brand name conventional is on sale at the time I'm ready to change the oil.