Tyre pressure plays an important role in both the lifespan of tyres and in the safety of the rig. PIC: Toyo Tires
Tyre failures caused by underinflated or overloaded tyres are a scary thing to experience and are an ‘inconvenience’ that can have serious consequences.
To make matters worse, such failures often occur when a vehicle, caravan or motorhome hits the highway fully loaded for the next adventure, bringing plans to a halt and placing the vehicle’s occupants – along with other road users – in potential danger.
Before we get into how an under-inflated or overloaded tyre may fail, let’s first look at the basics of how a tyre works.
Put simply, a tyre is a pressure vessel that contains air within it and, contrary to popular belief, it is this cushion of air that carries the majority of the load, not the tyre. Think of a tyre like an air mattress; overinflation causes discomfort by being too firm and under-inflation makes it easy to bottom out, with the perfect pressure being different for different weights and mattress sizes.
While both share a relationship between size, load and required inflation pressure, tyres differ from air mattresses in that they experience varying loads across a broad range of conditions and speeds.
As a tyre flexes in motion, it will generate heat that is easily dissipated if operating at the correct pressure but, if the load is too high or the pressure is too low at too high of a speed, excessive heat will build up and damage the bond between tyre components, leading to failure.
Where things can get a little tricky is when weight is added to the vehicle or trailer in the form of passengers, accessories, gear, supplies and consumables like food, fuel and water. A simple rule to remember is that if you’re loaded up, pump ‘em up!
It’s not uncommon for vehicles and trailers to be heavier than expected, so we recommend that motorists visit their local weighbridge when fully loaded to have the weight of each axle accurately measured. From there, it’s possible to calculate the correct inflation pressure for the load being carried with an adequate safety margin to suit likely speeds and terrain.
For Toyo Tires customers, we are happy to crunch these numbers to provide pressure advice free of charge. For vehicles carrying considerable weight or towing, we suggest high-quality light truck-construction tyres be fitted, especially when travelling remotely where conditions can unexpectedly deteriorate.
A few examples from the Toyo Tires range are the Open Country A/T II for travellers heading off-road, the Open Country U/T for sealed road tow vehicles or the NanoEnergy Van for caravans and motorhomes.
