Motorway range is where WLTP flatters EVs the most. Aerodynamic drag rises with the cube of speed, so going from 50 to 70 mph roughly doubles the aero power the car has to supply. That energy comes straight out of your range.
Our model computes motorway range from each car's drag coefficient, frontal area and mass — not from a lab cycle. That's why every car page has a dedicated motorway range card at 70 mph, separate from the gentler mild figure.
Add a cold month on top and the winter-motorway number is lower still. The methodology page shows the exact aerodynamic equation we use.