SINOPEC is a Chinese company but this stuff was made in Singapore. Not a brand most consumers would see unless they work the OTR trucking or heavy equipment. 18L (4.75 gal) seems to be the smallest quantity size you will find most of their products in.
As to why I chose it, 90% of it was the price point and sold on walmart.com and dropped shipped from a local distributor. It recently dipped for a brief moment to $55 shipped (normally $75) and I had a gift card to burn and bought it. That equates to $2.89 a quart.
I will be getting an aftermarket gear set in my Jeep Gladiator diffs that call out 85W-140 as the recommended grade. This will probably last me about 4 years. While I have not seen an oil analysis for this grade, there is a few floating around here for the 80W-90 gear oil, their diesel oils and hydraulic fluids and all show them to meet applicable spec. So I am not worried or have concern.