what unfamilia said times a billion!!! Having the outer sidewalls angled out like that means that the large flat surface that normally secures the tyres out beyond the bead won't work - If the tyre loses pressure, heck even on a massively hard corner with reasonable pressure, those tyres are just _begging_ to pop off the bead. To say nothing of the fact the sidewall and radial 'belts' are designed as a certain shape and distorting them like that will fatigue/stress them. AND the tread contact patch/downforce/spread will not be even across it's width.

This is without a doubt one of the most idiotic car related things I've seen on the internet. God help _anyone_ who has to share the roads with someone who does this.

To be fair, though, the ether 'deflagration' to pop the tyre onto the rim - believe it or not, that's actually not massively dangerous and is a reasonable way to seat a tyre on the beads if you are stranded in the outback or something (you'd have to inflate the tyre afterward as the rapid expansion of gas from combustion will of course cool/shrink/taper off, and it'll need more air in there to get it to desired pressure. This actually works out ok, because when far from civilisation, you might have a small pump on board which will inflate tyres, but has nowhere near the airflow to seat the tyre past the beads.