HA! Now I realize the difference - in desperation of avoiding a tow I test-fit my 850 spare wheel/tire but of course it didn't fit. That's an 850 wheel/tire laying against the rotor. Sorry about that, totally forgot until I just looked, thinking, what the hell is he talking about?! Did I mi....err, ...

Thanks for the elaborate reply Mo. It's the same tire, just different angles. 2, showing the spring plate mark, is showing the rub mark rather than the worn inside, so maybe that's confounding things. I spoke to a couple different trusted Volvo techs and there's consensus it's a simply alignment iss...

Yes, my 2017 S60 which I bought new has 40K mi now. Just had a flat on passenger front due to some crazy wear. I find it hard to believe it's an alignment issue. Just sent it to dealer and they say the solution is to run a harder tire. Wha?! Asinine. This is a design flaw if tolerances are so tight ...