Hey, if you want to pump up the MPGs a little and treat the engine a bit more gently, you could try using Amsoil UCL Additive in the gas. It's not good for a huge MPG increase, but I see you're already using 100% Gas.
I tried it in my explorer one tank, and I only saw a modest improvement from 17 to 17.7 (or 17.75?) MPG. That's 1 gallon in about every 600 miles, but it did work for something.
It's cheapest bought in bulk, of a case of 12, at Amsoil's 25% Discount. You can get it at $3.86 per bottle then.
It also quiets the engine a little, and it's supposed to prevent some wear in the valves.
https://www.amsoil.com/p/upper-cylinder-lubricant-ucl/
