Best brand of gasoline?

This is an old thread, but I'll use it rather than start a new thread. I'm in Utah where the gas is 85 87 or 91 octane. I fueled up with 88 octane to get ethanol free to try it. On the freeway at 80 mph I achieved almost 54 mpg. The best I did before that was around 45mpg. That is a 17% increase which is what prompted me to find this chat to see what others have said about it. (2026 LE AWD) According to dollars, I was only getting a 13% difference in gas price so it doesn't quite make it cost effective to put the 88 octane in. UNLESS I am going on long trips between pumps. And yes, that is a thing here in the west, especially when going through Nevada. You can stop at the little gas spots, but expect to pay much more for "convenience" gas.
On a side note: last year I drove a lonely highway through Nevada at 100 mph in my Infiniti and went a full 20 minutes before another car went by in the opposite direction. Don't stop though, the government did hundreds of nuclear tests in Nevada.

 

That's a big change that you are attributing to the lack of 10% ethanol.
Do you happen to know the wind speed and direction that particular day? A 20 mph direct tailwind could be the cause....

I have a different 88 Octane story: We were coming home from 3 days camping in the Ozarks in our new to us RV based on a Transit van.
I bought 15% ethanol, 88 Oct gas for $2.52/gal, which was cheaper than the normal 87 Oct w/ 10%.
It had a placard claiming 'It's fine for 2001 and later'....
30 miles into that tank the engine started bucking and popping and loosing power. It was flashing the CEL. I pulled over. It stayed running.
The CEL went out. We continued and it didn't act up again. I haven't checked to see if it stored fault codes.
I'm guessing a small gulp of water came along with this gas.
Next town I filled it up with No Alcohol 90 Oct for max dollars.... It only took 4 gallons, but I personally felt better.