285s different kind of mpg question

Hopefully someone here has experience with this. I've looked through the forums trying to get an answer about this with no luck. Before the usual suspects come out and tell me to get a Prius instead, I'm not looking for good mpg. I know and expect the mediocre gas mileage.

What I'm curious about, is that I currently have 265/75/16s each corner weighs in at about 68 pounds for both the wheel and tire. I'm considering going to the 285/70/17 Toyo at III SL which weigh in at 46-47 pounds. These will go with the factory style wheels 2020 pro replica that weighs in at about 19.5 pounds. This setup should run me at about 1.5 to 2.5 pounds lighter per corner. So I want to know if I'm missing anything or would this set up keep my mpg about the same or slightly better than what I'm running right now?

Thanks!

 

Less MPG, taller tire less torque and negligible unsprung weight reduction.

 

Remember to calculate your MPG using the actual Diameter of the old and new tires.

 

yup, like @Key-Rei said, less torque, harder to rotate the tires since they are taller. I've also heard wider tires make a larger difference in MPG than the skinnies at that height, so that's not helping either.

 

I knew I was missing something. Thank you @Key-Rei and @YF_Ryan

@toku58 I've been hand calculating using Google maps since I went up a size and it's surprisingly close to what the computer states

 

You’ll barely notice any difference if your 285s are only 46lbs approx.
Your truck will look way better with the 285s.