I recently had a bad experience with runflat tyres as a passenger in a friend's 2009 BMW 525 diesel. After the message saying 'check pressures', all tyres were inspected. All appeared okay with no obvious damage except one (the rear near-side) was warmer than the others. About a mile further on we tried to inflate the warm tyre but it would not hold air. So, having 25 miles to get home and with the handbook saying the tyre was good for 190km running flat with four (light) passengers we set off.

Most of the journey was easy, running through Leeds on a Sunday afternoon. There was no difficult terrain (steep hills or the like), but the tyre was completely shredded within 15 miles. Is this typical of the performance of runflat tyres? I also have them on my BMW 3 Series. Do you recommend buying a spacesaver and is there anything that can be done to preserve the operating life of the tyre whilst running flat? Can runflat tyres be replaced legally with conventional tyres?