A new tyre is one that has not been used Harry.
In my opinion however a tyre that was manufactured 5 years ago cannot be treated by a purchaser as new and in all likelihood does not conform to current manfacturing specification of a new tyre
. If you want a new tyre you should specify that it must have been manufactured within the last 12 mnoths and conforms with the current spcification for that tyre.
Similarly a "new car" can have been manufactured over 12 months ago,but has sat in a Compound somewhere, but is still sold "as new".So the thing to do is to specify that your new car must have been manufactured within the last 12 months and its spec is identical to the current spec of that model.
Just my view.