I was under the understanding that Phillips 66 Trop Artic, Kendell, and Motorcraft synthetic blend oils were comparable and manufactured by Phillips 66.
I used 5W-20, Trop Artic and Motorcraft synthetic blend regularly for a decade without any problems changing in April and November. All of these oils are getting hard to find at the heavily discounted price I was able to stock up, always under $2 a quart. I have a few oil changes left. I thought that I might switch to Pennzoil synthetic blend but I think it is also hard to find especially at a discount.
Now I am thinking of switching to Mobil synthetic. It is always available at Walmart or Costco at a decent price for a full synthetic and seems to work well for my application.