I use Royal Purple 5W-20 and Royal Purple filter...I change every 3K. However, I will change every 6months if I don't put 3K on the car in 6 months. I will say that from what I understand Royal Purple, K&N, and Mobil One filters are all manufactured by the same company and are pretty much the same specs. Also, Ford changed oil requirements from 2011 up to 5W-30, and all extended discussions, I like Torrie's (Unleashed Tuning) input best...use the oil that Ford recommends for your engine....