Range calculation is a bit jackanory at best. It also takes about 1500 miles for the range calculation to establish correctly and this is reset at the battery replacement. I don't know the exact calculation Ford use, but it will comprise of a static consumption figure, and at least two average period figures (say over 700 miles and over 1500 miles) to try to improve the accuracy of the prediction. Until these have built up it will be a bit inconsistent.PHEV my recall replacement battery is giving 66% of the 35 miles stated. Charges to different numbers but always goes back quickly to 24 miles available ??