Ok I know I’m a nerd when it comes to cars I work on them all day and restore them at weekends and I’m always reading about them so here’s a Web article I was reading today it’s a bit long and full of American jargon but the tire calculator info at the beginning is very interesting (if ya a nerd like me anyway)
That is the first explanation I have read that the author give a reason why additional flex in the side wall is a bad thing. Most people I come across have no idea why you increase pressure for sustained high speed or load. I also very much agree with there being no set pressure for inflation, however the max pressure less 10% would result in quite a few problems, plenty of tyres are 50 to 60 PSI A modern Golf would be running around on 45 to 55PSI.
The thing I come across very frequently though is that the contact pressure area is the same if the pressure is the same, regardless of the width.
Avon published data, which this gentleman incorporated into quite a long report, would disagree.
Hmm, in the real world the tyre contact pressures are unequal across the tread IF the internal air pressure is not “correct”. Witness the uneven wear on an otherwise correctly aligned wheel; the tyre will wear the edges first if under-inflated, and the centre if over. If the contact pressures were measured at different points across the tread and then compared with the internal air pressure the report would be more interesting. Then we could think about patch area.
Still, it is food for thought.
Modern radial tyres are far less suseptable to traditional under or over inflation wear. Wear is far mor likely to occur through suspension geometry or alignment. Take the Jaguar XF, the rears mainly wear in the middle and the fronts on the shoulders. Same tyre, same size, same pressure.