Just got back from our trip. Well over 2,000 miles driven in mostly 90+ degree weather, and some mountains. Timing was never pulled on 93 octane that I could see. Hottest the oil got was 241F while running high speeds at 95F ambient. Glad I had a 30 grade in the sump. Fuel mileage was also great again. We haven’t filled up in a few hundred miles, but through 1,780 miles at our last fill up we are getting a calculated 27.28 mpg on premium. Our van was packed to the gills and given the beans, often at 75+ mph (hypothetically)

. Was also driven slowly through a national park for a while doing some sightseeing, which knocked mpg down a bit. EPA highway rating is 26 mpg. I’ll fill the van up again in the next few days, but the last stint was driven more slowly given our route, and I’m only expecting our mpg average to go up.
Oddly, this trip has given me my greatest ever mpg discrepancy on this vehicle. On one tank, the computer estimated 30.4 mpg, while the calculated figure was 26.58 mpg. Maybe it over-filled at the pump, I don’t know.
What I can say is that the thicker ESP 0w-30 had no tangible effect on fuel mileage. Not that it should. Going to run it for at least a few OCIs.