I have a Kia Niro which I am taking to France this autumn and to France and Spain next spring. I don't wish to rely on the supplied tyre repair kit so have purchased online (not from Kia) a spare steel wheel and tyre. I have fitted it to the car to check that the rim actually fitted the studs, which it does, but the wheels diameter seemed smaller than the wheels supplied with the car. I telephoned the supplier to check that this wheel and tyre was appropriate and after checking told me that it was within legal tolerances and that it was okay to use. Is this right?

The tyre supplied with the car originally is 205 / 60 R16 the tyre on the steel rim is T125 / 80 R17 99M I would be grateful if you could confirm to me that this wheel is safe to use in an emergency to get me to a place where I can get the original tyre repaired or replaced.

I hope this information makes sense.