Poor gas mileage

So, if I am averaging 28 MPG for 50 miles of highway driving and replicate that for an entire tank of 14 gallons, that would be 392 miles! That seems impossible now but the math adds up?

The other interesting observation was that the street miles for this MPG test were 46 miles on the odometer, but the digital range readout only decreased by 23 miles which is exactly half. Can you explain that?

So, I filled up my tank for the first time since the hard reset and the digital range gauge got to 225 miles. Prior to that it's always been 167 miles. So, it added 58 miles. Not sure if that's an aberration or permanent. Several months ago, I had 200+ digital range after gassing up but every fill up after that it went back to 167.

Today I filled up for the second time since the Hard Reset and digital range reverted back to 167 miles. So, the 225-mile digital range after the first fill up was an aberration. Would I need to Hard Reset after each fill up to get the extra range?

Also, I drove 126 miles based on the odometer but only 97 based on the digital range gauge! There were some brief idling but nowhere near enough to account for the 29-mile difference. Driving was approximately 70% city + 30% highway. Can you explain the variance?

I will have an average MPG figure tomorrow when I fill up.

Yesterday I averaged 13 MPG from a combined work driving and many hours of idling.

Today I averaged 22 MPG from work only, comprised mostly of city driving and multiple brief periods of idling. My car's EPA MPG ratings are 27 Hwy / 22 City so it's consistent. Had I done this type of driving until an empty tank of 14 gallons, I would have traveled 308 miles and I haven't had that type of range for many months! So, I'm skeptical I would run out of gas long before that! This is encouraging but still leaves me baffled as to why that MPG average is normal, but the overall range is still way down?

What's strange is that with the last 2 fill ups, the digital range gauge reset to 167 miles just like it's been throughout this ordeal except for that 225 mile aberration after the Hard Reset. Then in the middle of my route, the range gauge abruptly went up another maybe 40 to 60 miles as I didn't notice it right away.

It is interesting that the digital range would adapt as if I were to take a long trip with mostly freeway driving, it would auto adjust towards the predicted 27 MPG / EPA rating. Perhaps the Hard Reset partially erased the memory of all the idling? For if it erased all the idling, it would go to 300+. I wonder if multiple consecutive Hard Resets would get it back to 300+?

I was also going to check how many gallons of gas are burned just idling the car continuously for many hours, filling up the tank right before and filling up again right after. Do you think this would reveal anything? I've checked several times and I lose about 4 miles of digital range per hour of idling but I'm not sure how that translates to gallons burned.

The tires are all stock size and all four were replaced two weeks ago with all-season tires replacing a very worn set of snow tires which might help mileage slightly as snow tires are made of softer rubber and might decrease rolling resistance.

Do you think a road trip to Las Vegas and back from Phoenix would help?