Go here for an education in engine lube oil and its applications:
One caveat about Wal-Mart's S-T brand oil filters: The supplier has been changed about a year ago and the newer product is not, in my opinion, good quality.
I use Motorcraft filters for the most part along with an occasional Wix or Purolator product.
BTW: If you want to run a long time between oil changes, then use a fleet-service oil such as Shell Rotella-T 5W40 full synthetic, the
stuff used in over-the-road diesels. The additive package in the oil is very robust and is designed in part to keep particulate contamination
in suspension (soot in the diesel). Any other oil classified API SM I would change out at 5000 miles intervals no matter what the manufacturer