Is the speed displayed on my HillSpeed HUD 09 correct on steep hills?
The slope of the ground (or roads) on which a vehicle is travelling gives no practical difference to either the correct speed or the speed displayed on the HillSpeed HUD 09. Even on a steep slope of 1 in 8 (12.5% slope), the difference between the horizontal distance and the distance measured on the slope is less than 8 metres in each kilometre (0.778%).