@Patman The Mobil 1 ESP X2 0W-20 is one of the thinnest 0W-20 oils around. It's been blended for absolute fuel economy. It doesn't make it bad by any means. It's probably very good oil. I only ran it once about a year ago and it worked as well as any other oil.
What I have found is the extended drain intervals are not so much up to the oil, provided it's a good quality product (Mobil1, Pennzoil, Castrol, Amsoil, etc.), as it is up the engine, sump size, filtration, fuel, and driving conditions. Some GDI and TGDI engine for example absolutely trash oil, and when you drive a vehicle like that in heavy city traffic, it completely destroys oil. All of a sudden you're happy with 4K to 5K oil change intervals, or even shorter.
In an old school port injected Toyota engine you can go 15K to 20K miles on an oil changed in mixed traffic, but predominantly highway. You can't do that in a Hyundai Theta II engine because some connecting rods might exit the block prematurely. You can do it in the Toyota with almost any name brand 0W-20, while in a Hyundai you'd have to do 5K intervals no matter what and go up a grade or two in viscosity. The same goes for some modern Honda engines, and I don't know yet what the deal is with the Turbo charged Toyota engines in their pickup trucks, and if they ever fixed the issue.