EPA MPG difference between 2010 and 2011-2015?

Huh, that's wild. I got my 2010 used just about 9 months ago. Granted, it didn't even have 90k miles on it at the time (I've almost got it to 100k now) and according the Dr. Prius app, when my battery has 8 bars (efficient braking off the highway to school for me, which is 75 MPH, will typically pull it up to 8 bars) that the battery has 75% capacity, so I assume that to mean that the battery has 75% of its charge left.

note that the EPA does estimate the rest of Gen III's as 48 MPG, thanks to testing differences, So that's what you'd expect (obviously you've hit below that though).

I know a lady at my work that owns a 2011, and she says she usually gets 40 MPG; but when I follow the ECO indicator (keeping it on unless I need the extra power for safety reasons), I get 60-70 MPG in the summer, 70-80 with Pulse & Glide, 50-60 in the winter (unless it's REALLY cold, I'll get to that), 60-65 with Pulse & Glide.

When I drive "like a normal person" (following traffic, accelerating as fast as everyone around me) I still struggle to get it below 50 MPG. That's in the summer. In the winter it does get more like a 40-50 MPG range, but the average comes out to 45 still.

You may remember when Texas had its entire electrical grid frozen during the ice storm a few months back. Oklahoma had that too, except our grid is connected to the nation so we generally had more minor shortages. During that cold week(s?), where the temperature was something like 5F to 15F (-15C to -9C), I typically got 25-35 MPG, 40 at best, as a result of heating the cabin, engine warming, and mostly running the defroster for forever without going anywhere thanks to 4-6 inches of snow on the car. Still easily better than the 2013 Corolla I was driving beforehand would have gotten.

I would put it up to traffic differences, except there's the lady at my work who gets similar numbers, so I have no idea. The Prius has been better in gas mileage than I would have hoped, although part of that is because (as a younger person) I genuinely hate engine roar, so I tend to be light on the pedal anyways so that I don't have to hear that. Given that, I am also very excited for practical BEV's. Maybe an EV Prius with Toyota's incoming Solid-State batteries...