Are you accurately checking
Are you accurately checking the mileage at each fill-up?
That is the best way to check mileage. Also it is good you try to go the same gas pump when you fill up and check your readings.
I have 7K miles and rarely get 37 mpg. It is mostly 33-35 mpg. Very disappointing.
I know someone else you get the same milage. Toyota needs to hear from us on this.