If you read the last sentence of the first paragraph, "Premium fuel will provide improved performance..." Improved performance is more HP and better mileage. It will take about 2-3 tanks of premium for the truck to re-calibrate its tune if you were running 87 octane before. I was running 87 octane at first then I speaking with one of my friends who was an engineer on the 2018 Raptor project. He mentioned that the truck will be able to make the full 450hp on 92 octane premium otherwise it'll only make about 390hp on 87 octane fuel. I switched from 87 to 92 octane then did a road trip (Detroit to DC). I got about 17 mpg on the highway with a tank of 92 octane after switching going there. On the return, I filled back up again with 92 octane again and noticed my mpg was 18.7 mpg on the highway. I ran adaptive cruise set at 6 mph above the posted speed limits both ways for most of the trip. Detroit to DC is one tank each way in range. Right now, I'm averaging 16.3 in the city on 93 octane. I chalk up the lower mpg due to a couple of factors: - temps are freezing in this area, gas stations are selling their crappy winter blend. Winter blend has cheaper butane added to prevent freezing. Butane has less energy. - I let the engine warm up 5 minutes each morning(m-f autostart via FordPass) before driving to defrost the windshield. (0.1 mpg drop each morning) -and lastly because temps are freezing and there's snow/ice on the roads, I run 4A or 4H which requires more power thus burn more fuel. I'll have to re-visit this again when the temps are up and Summer blend is available again.