In my old K1500, I change the filter twice a year (Napa Gold) and run my truck about 10k miles a year. She burns a quart every 600-800 miles, so I change the plugs often, and the oil never.
I would use a 10W-40 high mileage oil in winter, then maybe start using 15W-40 when it warms up and change it at least once a year with a good filter...