How did my car get 60MPG recently? Is the trip computer broken?

How did my car get 60MPG recently? Is the trip computer broken? - 1

Added (1). My car is a newish Honda Civic with EPA rating of 39MPG on highway but I recently got 60MPG during a 70 mile freeway trip. How was this possible?

Maybe you had a good tailwind. Doing 70 mph with a 20 mph wind at your back is like driving 50 mph. The lighter your foot, the heavier your wallet.

I suspect that you misread the system and it only read and INSTANTANEOUS reading of 60 mph while going down a steep grade at highway speed. You could have probably shifted to neutral and turned the car off and maintained speed on that particular stretch of road.

No. You just were high and can't add subtract and multiply.