Nice! Mine at 8k miles but only around 110 mpg. Mostly 75% highway miles with elevation change of 2500 commute to work.
In summer 2018 I had 5310 miles on the odometer and avg mpg of 150.6. I now have 6,300 miles (1 year old) and still averaging 150-151 mpg.
I have only had my Prime Plus for a bit over a week now, but I am finding the overall MPG number as stated on the dash to be very meaningless. With the old Prius (I had one) you could compare easily and actually be impressed with 60+ numbers. Now you really can't tell whether someone is a miracle hypermiler or not and it is just a reflection of how many miles you are able to drive in EV mode as opposed to using the ICE. Do you only use your Prime for very short rides: yay 999.9 MPG! I really wish the dash would show two numbers next to each other: one in MPG for distance driven on the ICE and one MPkWh for distances driven in EV. That would really allow a comparison.
I agree with you. It's a pet pev that I've had when going through my OPEX analysis of purchasing a Prime. I like looking at things in $/Mile of operation. At least variable cost things.