Wrong? I don’t think so. I live in Texas. People here do 85-90 mph on a 75 speed limit regularly. You can’t achieve 25 mpg fuel economy with that speed. 😎
I cannot, for the life of me, get not even 25 mpg on the freeway. Yesterday I went to San Antonio... I think the best I had was 23, maybe 24 mpg... For me it's such a joy driving the turbo that I can't stay put doing 65 mph. No way Jose!
My bad, I know that Samsung is Android. I don't know why I was under the impression that you have an iPhone. If you say both cellphones have the same settings, check the software, maybe there is a software version difference between yours and your wife's phone.