Does anyone know how the AVERAGE speed is calculated in the Mini computer? It does NOT appear to be distance divided by time. It looks like it is calculated using the speedodmeter rather than the odometer.

 

The odometer data is only accumulated miles... no time reference. The speedometer is miles/hour. My guess is that it is sampling the speedo data at some interval and averaging. It is only using the time when the car is running. I believe it starts rolling the average after enough data is accumulated, like it does for mpg. That is why it shows and average speed of say, 50mph, but when you drive it 10 miles at 35mph, it only lowers the average slightly from 50mph depending on the last time it was reset.