'Mobility tyres' are otherwise known as run-flat tyres.

Basically, if you get a puncture, you shouldn't suffer a complete deflation, as the tyre has a stiffer sidewall and can thus be driven on to a place of safety/a garage, etc.

The upside is that you are less likely to get wiped out on a motorway hard shoulder, etc.

The downside is that the tyres are more expensive, they generally have a harder ride (that stiffer sidewall again), and, if they have been driven on for any appreciable distance whilst flat, they can't be repaired and must be replaced (preferably in pairs). Also, lots of tyre depots won't repair runflats under any circumstances, and will insist on sendng them away for a specialist centre to do the repair.

Is it me, or is anyone else underwhelmed by the idea of tyres that seal themselves but need to be repaired (these Conti Seal thingies), how exactly are you to know that the tyre has sustained damage if it's sealed itself, personally i'd rather the bally thing deflated at the time instead of carrying on with the damage sealed but possibly getting worse and the tyre then may suffer a sudden instant failure.

I can understand armoured or security vehicles having puncture resistant and self sealing tyres for obvious reasons, and no doubt those things are checked carefully by people who know what they are looking for after use, i have every intention of sticking with regular tyres for the rest of my time behind the wheel.