It is also my understanding that high mileage oils are at the top end of their viscosity range for their rating. If you go much thicker you might end up with a 5W30 or something???
You could get really scientific and send in an oil analysis to a lab such as Blackstone and see what is really different about these oils. You might end up liking a tad thicker oil for those high speed drives.
It is my understanding that Mobil 1 comes in FOUR different types for 0W20. I have a car that also takes this oil and did some research. All are very good oils but some might be better. The two more basic ones are the Advanced Fuel Economy (AFE) in a bottle with a green label and Extended Protection (EP) in a bottle with a gold label. My research indicated that the oil and additive package is a tad better in the EP flavor so that is what I have been using even with the possible expense of some fuel economy. It can be bought in the 5 quart jug at Wal-Mart for around $22-25 depending on the day and store location it is purchased.
Then you have the high mileage formulation as will as the Annual Protection. You are supposed to be able to go a year without changing on that one and it is quite a bit more costly so I have never bought this. It may be great oil but doubt this is needed. My car is also under warranty and those change intervals might be an issue even if the oil and filter are good for it.
You can also watch for a rebate for up to $17 off the cost of 5 quarts and a filter. They do this twice a year and allow two rebates per address each time. I always max out my rebates to have some changes in reserve. Be expecting the fall rebate to be coming soon. The $17 off is currently listed as expired but you can see the details at https://mobiloil.com/en/promotion/mobil-promotions This basically negates any price premium of buying synthetic oil over conventional and is too good to pass up.