One of the first things we spent time on during a Defensive Driving course I took was tyre pressure. Apparently the manufacturer's recommendations are low - something to do with ride comfort I gather.
We were told that instead of 26psi, 35psi was safer to avoid hydroplaning. For full size four wheel drives using light truck tyres, 45psi is preferable to the usual manufacturer's recommendation of 35psi. It seems that when brakes are applied suddenly and forcefully, the road surface of underinflated tyres will curl up in the middle so only the outside rims of the tyre rubber actually remain touching the road. Hence the hydroplaning effect when the road is wet. Inflating to the recommended pressure is meant to prevent this curling up.
We were told that instead of 26psi, 35psi was safer to avoid hydroplaning. For full size four wheel drives using light truck tyres, 45psi is preferable to the usual manufacturer's recommendation of 35psi. It seems that when brakes are applied suddenly and forcefully, the road surface of underinflated tyres will curl up in the middle so only the outside rims of the tyre rubber actually remain touching the road. Hence the hydroplaning effect when the road is wet. Inflating to the recommended pressure is meant to prevent this curling up.