I have a 1998 V6 4WD that I use as a daily driver and I also 4 wheel it. I'm currently using Mobile 1 5W-30 every 7500 miles with a M1 filter as well. I'm considering changing to Amsoil Series 2000 0W-30 because I hear I can get away with changing the oil once a year and changing the filter every six months. WHat should I use? Thoughts?