I was hoping to get some opinions on allowing extended oil change intervals with synthetic oil. I of course realize that during the warrantee period one must closely adhere to the manufacturers recommendations, but Im talking real world here. In my own case, I own a 2001 Ford Explorer Sport Trac (4.0 L SOHC engine) . Since 1100 miles I have been running Mobil 1 synthetic 5W-30 weight oil with a Motorcraft FL820S filter. Since I drive less than 7500 miles per year, I intend to change the oil and filter ONCE per year. Seems from all that Ive read, Mobil 1 should easily be able to handle a year in the crankcase with capacity to spare and should still provide superior protection and hopefully allow long term engine longevity on this schedule. I welcome your opinions and thanks in advance for your answers.