The figure shows different driving situations on a wet road. The first case involves a good tyre tread pattern at a velocity of 80 km/h (50 mph). The approaching zone has a length of approx. 12 mm (0.47 inches), the dry contact zone approx. 68 mm (2.7 inches). At a speed of 150 km/h (93 mph), the approaching zone has already lengthened to 18 mm (0.71 inches). In the absence of a sufficient tyre profile (case 3) at a speed of 80 km/h (50 mph), there is already a closed water layer between the tyre and the road.
The resulting wheel resistance on wet road is added by the baffle resistance force and the rolling resistance on dry road: