Tire wear, Passat 3B sedan, 1998, 110 hp AFN engine

Hello everyone,
Regarding the Conti Sport Contact 205/55 R16 91 W tires, I have the following problem: The rear tires become so 'serrated' (with a saw-like pattern) at a tread depth of approximately 4 mm, that the resulting rumbling noises are very annoying. Driving style: quiet, mostly highway driving, very low wear (85,000 km with this set). Shock absorbers checked on a test stand - OK. Does anyone know about this problem? Does it lie with the tire manufacturer? Which tire can be recommended?
Best regards,
Kradmelder

[Translating...]das problem gibt es nicht nur bei diesem reifen. ist typisch für reifen in blockbauweise, die 'ewig' auf einem auto an der hinterachse sind. mein tip entweder reifen mit v-profil kaufen oder öfters von vorne nach hinten wechseln.

ixery