The OP seams to be living in an area where the ambient may get too hot, and high running maximum tire pressure in hot weather is a good idea as it cuts down on additional heating of the tire by cutting down to the flexing of the rubber.
The run maximum tire pressure comes from driving trucks many years ago, working for a fly by night cheap cement, stone, and construction material company in a local state known for poor regulations regarding vehicles. That company had two identical trucks each with a 28 foot flat bed attached to the cab (not a removable trailer) and no pivot point behind the cab. Those trucks were rated for a 10 ton load. One day they put 20 tons of rod-iron on one of those trucks and sent someone out to deliver it on the other side of the state. It turned out to be a very hot day in the upper 90's F. These trucks were single back axle (and that axle was the drive wheels), with dules (four wheels two on each side of the back axle). The first truck driver did not put 15 PSI over rated in the tires and got about 80 miles away and blew out three of the four back tires. The boss tells me to get the other flat-bed and be sure to put 15 PSI over maximum rated pressure in all tires, and then go to where the broken down truck is and the first driver and I are to transfer the load by hand to my truck, and then I am to deliver it. The company mechanic will be about ten minutes behind me and he will help in the transfer. I went there and we began transferring 20 tons of rod-iron in 99 F heat with the sun shining hard. This was on the side of a highway not near any city. Soon after we started the transfer two local young men walk up and ask if we could use some help. I told them that I did not have much extra money to pay them, and they said that is ok, if they wanted money they would of asked before offering the help. I still paid them all I could after we were done. Then I told the other driver to watch the trucks while I walked across the road and dove into a lake clothes and all. The two locals said that I should not swim in that lake, that there was something going on with it but they did not know the specifics. I dove in anyhow. Then I went back to my truck and began delivering the load. In a short time I was dry from the hot wind blowing through the cab with the windows open going down the highway.
The speed limit then was 55 nation wide, and the local rule of thumb was keep it below 64 and you would be fine. So I kept it at 61 to 63 MPH. After about 10 to 15 minutes of driving the back wheel would start to slide some like they were on ice. This was because the rubber was getting so hot that the tires were sliding. I would pull over and stop for ten minutes and let the tires cool off. Then drive for about 10 or 15 minutes until the back tires began to slip again. I pulled over to let them cool for ten minutes each time I felt them slip. After the sun set the tires did not over heat any more, and I could drive without stopping.
I arrived at the work site too late. The crew building the swimming pool were gone for the day and there was no one to run the equipment to unload the truck, so I ended up sleeping in the cab until they showed up the next morning.
While I was young and dumb to work for a company that over loaded trucks like that, one thing I learned was to run the air pressure high to reduce tire over-heating on hot days with a large load. If the tire pressure is too low, the additional flexing of the rubber adds too much heat and the tires will blow out.
There are several other stories about that company I could tell such as rolling over a front end loader, or people rolling over a cement trucks. It is amazing no one got killed or even seriously hurt with all the things this company got away with.
