I came across an interesting video on YouTube from a guy who is always testing lubrication products. It looks like Amazon is now selling full synthetic motor oil under their "Amazon Basics" brand. He ran some rudimentary tests and it came out almost identical to Mobil-1.
A 5-Qt jug of 5W-30 full synthetic is $17.27 with free Prime delivery. That compares to $26.61 for Mobil-1 from Walmart.
Is AmazonBasics Full Synthetic Motor Oil better than Mobil 1? Lets find out! - YouTube
Amazon.com: AmazonBasics Full Synthetic Motor Oil (SN Plus, dexos1-Gen2) - 5W-30 - 5 Quart - AM0D533Q: Automotive
Who would have thunk it?