Tyre age, when to change, and when new ??

Does it feel a bit slippery in the corners?

When I bought my car, its OEM Potenzas were six years old and only half worn, and because it had always been garaged there were no cracks or perishing visible.  But I was not happy, because it was a bit slidey at either end, and noticeably twitchy.  Four new tyres transformed the car to feeling like it was planted on rails and always totally secure in any direction I point it; now I’m very happy.

They are the only things holding you on the road.  Always have the best tyres.  IMHO no-one can afford not to!