You wonder just how new they are when they issue them.
I think most tyres are unused when sold , but if they have been stored in the wrong conditions for a long time before sale they may not grip as well due to hardening , and be more prone to failure...
Formula 1 tyres are an art , a race can be won or lost on wrong tyre choice , and no , they don,t last long...
I competed in formula 5000 , which is whats now called formula three , for a few laps to decide grid position we would put on the softest tyres , which give the most grip , and thrash it round the track.. After this the tyres were shredded and useless..they cost 650 quid each...!
After the race the engine was pretty well shot as well...