That may be a small squeak from the recirc valve, normal. When I let off the gas on my 3.5L work truck from a quick acceleration it makes the same sound, a bit louder and noticeable when the windows are down.
I would hand calculate after filling for the most accurate mpg. Here is my Fuelly is you want to check it out. All fill ups are premium top tier fuel. I get about 24.5 mpg per fill up right now.
https://www.fuelly.com/car/ford/ranger/2025/jim87/1393678
I can, for a sec, then the wind noise from the mirror area drowns it out. It is a little better in sport mode, but not much. This is with front windows down, all stock.
I just used mine this morning, very helpful. I used the driver side, left foot on the step, other foot onto the tail gate, never got caught on the cable. There is enough room where you won't get tangled.