I don't keep average MPG even though I calculate nearly every fill. I've been travelling in sunny Florida and getting terrific mileage in my 2001 Accord 4cyl MT with 270K miles on the odo. I assume Florida fuel is a year round formula, seems to be giving some of the best mileage this car has ever gotten.
The driving conditions are ideal to obtain high MPG for this car, warm but A/C not mandatory, slower speeds (45-60) without many stops. I've gotten 36-37 MPG on several fills, but the last fill will need to verify it was completely full on the next fill before I can believe it. It was 42 MPG.
Amazed with that number, it verifies great cylinder sealing for an engine with 270K miles. Impressed that this high miles engine got the best mileage since the car was bought new.