I have to say I've been impressed by how long they have lasted especially being used all year round where you would expect them to wear quicker . One of the rears had faking powdercoat causing a leak and i found the inside edge on that one is smooth but the other wearing more evenly . They are non runflat budget winter tyres made by rotalla (Ice plus s220) adn id buy them again
By comparison the last set of fronts only lasted 5k before the outside edges were scrubbed off and this was due to running runflat pressures (32)which are far too low for non runflats . I pump these to 38/39 psi and that seems about right to get good life and not trash the inside edges.
Of course it rained the whole hour it took me to swap them over and damn these wheels are heavy the 21's I put on the rears are 38kg each ! A locating dowel I bought to screw into the hub makes life so much easier and all the bolts undid easily as I torqued them to 140nm not 3 ugga duggas the tyre shops use on everything
and the last wheel in the stack I went to fit had gone completely flat after 18 months with 120kg on top of it
Yes I know you should stack them on the tread but I don't have the room and they tend to fall over and damage the faces.
Really need 3 tyres now may call it 4 and one wheel is badly corroded , another a bit corroded and the other 2 are ok . Don't think the car will last another 30k though 
with a rumbling transfer box , broken aircon and a rusty bootlid corner 