[Wenger786]

I need to replace two tyres - currently 175/55 R14 T 85 (Continental Eco) I think.

car owned by govt agency (second hand).

I looked at the spare but it's a different size on a 13 rim i think. is this "normal"?

 

[Walksall]

What you have found in the boot is an 'emergency' spare - purposely made smaller to fit in the boot - I know, not ideal, but some cars don't even have a spare wheel these days (they give you a can of tyre sealant instead)
You are not supposed to drive at more than 50mph on these things and get them changed ASAP.
I would also advise that you always fit them to the REAR wheels only (even if this means changing wheels around) - particularly important if you MUST drive for long distances. - Failure to do this may put excessive wear on the differential.

Regards