The car also went for a service yesterday at my local independent (sorry, DIY advocates
).
I suggested they do a tyre rotation as I knew my fronts are getting pretty worn down, and the rears looked to me to have a little more tread depth left in them.
I got a call back to tell me my rear tyres are "lumpy" and it would be unpleasant and even dangerous to drive with them on the front. He called it "radial warp", but I think the Googleable term must be "cupping" for uneven wear most usually caused by suspension or alignment problems. I have the described characteristics, being a lot of road noise in general and "whump whump whump whump" at speed. (My mechanic reckoned it was unbearably noisy, but I guess I just don't know any different...)
It's not clear why the tyres went wonky, as a simple bounce test suggests the shock absorbers are okay... I'm a bit worried there's something expensive to be revealed under there. All four tyres are practically finished anyway so will get a new set and probably an alignment check and see...
The current tyres are Michelin Primacy HP manufactured in 2012, so they've likely done 57,000 km assuming they were fitted at the '13 logbook service (before my ownership). The car itself is now at 116,000km and 8 years old...