The pure fuel will 90% of the time come from the same source of a local area. Each brand will normally mix their additives in the tanker truck. So, yeah.The good old days when I posted this. Actually I was questioned about asking at the time when it was on Hyundai's site. Well at the time I did not have the car yet and was looking at a 2012 and a 2013. The 2012 did not mention both grades of gas only the 2013 site had it.
As for the poster said 89 better additives, not really true, just the brand of gas matters like the top tier stations like Shell and some others which I forgot have more additives.