Rolling up on 5K on the PB and time for its first oil change. I have three jugs of Kirkland full synthetic 5W-30 from my Maverick left over. I plan on using it on the next three oil changes. And grab a bottle of 5W-30 synthetic Motorcraft from work with a Fram ultra filter cause the truck takes 6Q. You say 5K is a good interval for Kirkland or go shorter/longer?