Since I upgraded the suspension of my Signum (springs and shocks) to the factory Sport, the life of my rear tyres is being reduced dramatically.
This change was did by a Opel dealer. They have updated the chassis alignment values to Signum with "Sport" equipment.

I've used three different brands (225/45/17):
Good Year Eagle F1, not more than 16.000 km
Falken ziex 912, around 14.000
Continental Contisport (now) I don't believe that they can last more than 18000.

The wear of tyres is not uneven.

I don't have read in the forum another case like this.
Any idea will welcome.