Here’s how it works. Measure tyre pressures cold, before the start of the trip. In our case we get best results if we start the van tyres at 50PSI. Then after a few hours of travel they should have gained no more than 5PSI. That indicates that as the tyre warmed it caused an increase in pressure but not so much so as to over-inflate the tyre, causing excessive heat and eventually tyre failure. All van tyres were at 55PSI, indicating that we were not overheating the tyres and we were safe to continue at that pressure.
Incidentally, using this rule we have never blown a tyre or had a heat-caused tyre failure in all our years living in caravans. We’ve lost a tyre from echidna spines. The poor little bugger was already dead when our van wheel rolled over him when we were travelling off the beaten track. Tyre repair technician explained to us that the spines had penetrated the sidewalls and many places on the tread he would not repair it.
