While I agree with some of your info... I am also a pilot (multi engine rated) and I am not really sure that you really can compare a gas power aircraft using av gas to a ground vehicle using formulated for EPA standards automobiles gas.... but I do understand you concept (theory applied) thoughts.
But vacuum gauge can increase your MPG (or the digital IMPG display)

The other thing not sure back in the day heating your gas helped in fact it was the opposite if you wanted to generate a sustain power level as well support better developed HP which translates to increased MPG. That is the pilot theory applying to a ground vehicle coming out in you perhaps? But can't say back in the 1970s-80s even into the 90's I was concerned about MPG or cared even when we had even odd day to get gas. You should remember that fiasco BS?

 

Hello - 2026 Mazda CX-50 Premuim Gas, just over 1000-miles, my mileage was around 23, now it has crept upto 25.9MPG - is there a break-in period for these engines and transmissions? I haven't had it up over 4000RPM or over 70MPH - trying to be nice to this one... and I'm hoping for a better MPG.

 

Your or to make a blanket statement 2.5 2024 engine as far as most engine in terms manufactured methods and most materials are generally or basically the same from as far back as 2014. This information and servicing is how they should be considered.
Change the oil and filter at least early at 3000 miles and then 3 or 5000 miles. Try not to get influenced by what is on the internet and Mazda forums.
At 13k miles or sooner find an independent ASE certified service shop to do a simple transmission filter and pan fluid change. this *will not affect your warranty in any way and regardless of the claim of lifetime no service needed IT DOES!!!*See: e Magnuson–Moss Warranty Act (15 U.S.C. §§ 2301–2312) is a U.S. federal law
Ask the service person to see what has accumulated in that short time at the bottom of your transmission pan and pan magnet.
You can also invest in a simple oil sample analysis (well worth the very small cost) to have both your oils analyzed.

Oil Analysis | Blackstone Laboratories


The engine needs from what I have collect information from using various testing equipment and monitors on a few 2.5 Skyactiv engines 2014-2018 about min. 3000 miles but closer to 5000 miles. You will see trends in per4fromance as you get closer to the 5000-mile mark in power as well MPG. And again, this is based on a simple Dyno check a couple of new Mazda's including mine and noting the changes at those miles.

To reduce the DIY and casual member responding in the other directions regarding my recommendation I suggest reading the thread below and make your own judgement on the information provided by members even mine
Car Repair Advice Forum= at your own risk - Mazda Forum - Mazda Enthusiast Forums


These are simple services for your $$$$$ investment in the new Mazda to at least prevent many issues in the future.