What that means is Motorcraft is a semi synthetic and still is decent oil but it vaporizes more readily at lower temps then PP or UP or Mobil1 Vanilla or Mobil1 EP in a 5w30. Similar to the situation with Nissan's "special" Ester oil only they price theirs like unicorn tears, the oil will work fine but most any off the shelf synthetic from the major makers or even Supertech or Amazon's blender in an SN or SN+ will likely offer more high rev/temp performance