I have a 2002 F-150 with 67,500 miles on it. The truck has never pulled anything, and has the 4.6 liter V8. I have always had the oil changed every 5K. I have always used regular Valvoline 10W-30, except at 25K. I used Mobil 1 Extended and kept it in for 10K before going back to the Valvoline. My daughter is now driving the truck. She will only put 4K-5K miles a year on it. Since it will only be driven so few miles, I am thinking of just changing the oil once a year. I am thinking of going to Pennzoil Platinum, 5W-30 with a Purolator one filter. Or should I change it every 6 months using regular oil like Mobil clean 5000 along with a MC filter?