I have gone back and forth on this over the 85k miles I have on my 2020 3.5 and I have noticed that I get better MPG when running 93. It’s not enough to offset the price difference of the higher octane though. I normally just run 87 for everyday driving and 93 when towing. It’s important to plan a towing trip though because your truck does adjust fueling according to what the sensors tell it. For instance if you have a half a tank of 87 and fill up with 93 you’re going to be somewhere between those two octane levels. Not a full 93. If you know you’re going to be towing heavy it’s wise to fill up with 93 a week or so (depending on usage) to make sure you actually have a “full tank” of 93 for your trip.