After buying brand new tyres and driving 6-12 thousands miles with them suddenly a humming sounds comes. The main cause probably the sawtooth pattern abrasion of the tyres. The lateral drains forms isolated blocks on the yoke of the tyres. While the tyre is rolling on the road each single blocks are deforms as they reach the road surface and pressed together. When they leave the road surface „grazing lightly” the surface during regaining their origin shapes. These blocks can abraise up to sawtooth pattern in certain conditions as a result of the rolling mechanisms. Such conditions are for example driving on long and straight roads with permanent velocity (motorways), moderate driving style, the adjustment of wheel inclination.
The heavy sawtooth pattern abrasion usually develops in given circumstances (e.g. low tyre pressure, exaggerated wheel convergence, useage causing less attrition). The load of the passenger cars are designed for 4-5 persons, so if you often drive alone or with max. one passenger the tyres are not get enough load. The situation is the same if you often use a van without load.
Wowtyres Tip: It is useful to shift the front tyres with the rear tyres after 3-4000 miles usage (please, consider the suggestions of the user’s manual of your car).