Tire Pressure - MAX vs DATAPLATE
A LOT of replies to tire threads recommend running the trailer (and I assume also car/truck/motorhome) at sidewall max psi instead of the dataplate psi. Why? My trailer tires have a max psi of 120....
Forum Discussion
To my conclusion the sheer forces are not the reason why the tires damage, if the stucture is undamaged that is.
The damage of the structure of the rubber of the tire is courced by to high temperature at critical rings of the tire , the tire produces more heat that can be cooled down , by to much deflection ,or better bending of the rubber,times number of cycles the tire makes a second.
Especially ST tires are calculated in their maximum load for more deflection allowed at the lower speed of 65m/h.
Asuming this calculation is right done, then still its to the edges.
If then some overloading on a tire, or lower pressure cold( misreading of scale or inacurate device) and the deflection gets to much so to much heat production and temperature of the critical rings gets to high and rubber hardens , and at next bendings , so deflections cracks .
Then when sheer forces , even at the lower speeds they happen, these cracks tear the tire apart.
Best is to give the ST tire a pressure of the given pressure of tire, to build in some reserve so it wont get to hot. Even the 10 psi higher or for truck tire 20 psi for 75 m/h can be needed , even if you keep yourselfes below 65 psi.
for your normal car the 51 psi is the maximum cold pressure and not the pressure needed for the maximum load , this is for P tires always 35 psi ( american TRA system), and there they are calculated for 99m/h the deflection. Because you probably never drive this speed, so for normal cars the pressure can be lower then max given.
The damage of the structure of the rubber of the tire is courced by to high temperature at critical rings of the tire , the tire produces more heat that can be cooled down , by to much deflection ,or better bending of the rubber,times number of cycles the tire makes a second.
Especially ST tires are calculated in their maximum load for more deflection allowed at the lower speed of 65m/h.
Asuming this calculation is right done, then still its to the edges.
If then some overloading on a tire, or lower pressure cold( misreading of scale or inacurate device) and the deflection gets to much so to much heat production and temperature of the critical rings gets to high and rubber hardens , and at next bendings , so deflections cracks .
Then when sheer forces , even at the lower speeds they happen, these cracks tear the tire apart.
Best is to give the ST tire a pressure of the given pressure of tire, to build in some reserve so it wont get to hot. Even the 10 psi higher or for truck tire 20 psi for 75 m/h can be needed , even if you keep yourselfes below 65 psi.
for your normal car the 51 psi is the maximum cold pressure and not the pressure needed for the maximum load , this is for P tires always 35 psi ( american TRA system), and there they are calculated for 99m/h the deflection. Because you probably never drive this speed, so for normal cars the pressure can be lower then max given.
