Old-but-new spare tyres

marlot

Over inflated is good on spare wheels (as long as its not higher than the maximum the tyre can take). Much better to find its over inflated than underinflated when you need it at the side of the road.

It can be worth watching ebay or visitng a scrapyard for a matching alloy for the spare wheel - makes it easier to use the spare as an everyday wheel.

Gloomendoom

Sunlight kills tyres.

If the tyre has been kept in the dark its life expectancy will be a lot longer than the same tyre exposed to ultra violet light.