I have a 2000 Lariat 5.4L with 163,000 miles. I had to have the air conditioner recharged for the first time yesterday. These trucks continue to amaze me. I use the A/C seldom, but when I need it I want it to work. I am wondering if the fact that I use the A/C so seldom that that is the reason for the longevity of my charge? Or...am I just lucky?