Our grandparents would agree that they're a modern miracle: tires that keep on turning even when they're flat. But how exactly does a run flat tire work?

We paraphrase 2023 Ford Bronco Sport owner M.A., who counted his blessings after a huge hole took out his tire. Is this a good reminder that spare tires serve a useful purpose?

RFT tires can run even with a puncture, but they're less comfortable and require a TPMS for safety. Thus they may not be suitable for all cars.

Mushroom patch? String repair? Sounds like something for the kitchen, not your premium run-flat tyres, right?