I am a South African (Cape Town, Western Cape) owner of a 2011 159 ti which currently has some 22,000km of which 67% is long distance. I had to replace the front tyres at 11,000km, had the rear tyres swopped to the front but at 18,000km was forced to swopped them back at 18,000km. When I took this up with the dealer I purchased the car from I was told that Alfa Romeo SA told them that the best I can get will be 20,000km from a set of front tyres. I took the car to another dealer in Cape Town and was told the same.
I am rather disappointed in that every 10 months I will have to spend some R7,500 or 625 pounds on new tryes which is very expensive.
I am going to take this up through the two major AR clubs in South Africa and see if I cannot get a better answer from Fiat/Alfa Romeo SA as well as find out what other 159 owners have experienced.