The Critical Role of Proper Air Pressure in OTR Tires

For heavy equipment in construction, quarrying, and mining, tire maintenance is not optional—it’s fundamental. Among the many variables that influence tire performance, none is more critical than air pressure management.

Triangle Tire, one of the world’s leading OTR tire manufacturers, stresses that proper inflation is the single most important factor affecting safety, tire life, and overall operating cost.

Under Inflation

Excessive Sidewall Deflection

Excessive Sidewall Deflection
Under-inflated tires flex more with each rotation, creating heat buildup within the casing. Elevated temperatures degrade rubber compounds and weaken steel belts, accelerating structural fatigue.

Irregular Tread Wear

Irregular Tread Wear
Reduced internal support shifts the load onto the tread shoulders, wearing them prematurely while the center rib remains relatively intact.

Reduced Load-Carrying Capacity

Reduced Load-Carrying Capacity
Even modest under-inflation significantly reduces the rated capacity of the tire, increasing the probability of overloading.

Over Inflation

Reduced Contact Patch

Reduced Contact Patch
Higher pressure reduces the footprint, concentrating the load on the tread center. This not only causes faster center wear but also reduces traction.

Impact Damage Risk

Impact Damage Risk
Over-inflated tires are less able to absorb impacts. A sharp rock or edge strike can shear chunks of tread or cause casing rupture.

Increased Stiffness

Increased Stiffness
Excess pressure transmits more vibration to the machine, which can cause operator fatigue and mechanical stress to the chassis and suspension.

Tire capacity is not static—it varies with both inflation pressure and speed. A tire inflated to 40 psi, for example:

At 30 mph, is limited to carrying approximately 3,100 lbs.
At 5 mph, the same tire at the same pressure can safely carry up to 11,700 lbs.

Tire capacity comparison at different speeds

As speed increases, carrying capacity decreases at any given pressure. Operators and fleet managers must always align tire inflation settings with both maximum load and maximum speed to avoid overload conditions.

Triangle Tire USA recommends:

  • Establish routine pressure checks using calibrated gauges, ideally daily or before each shift.
  • Adjust inflation to reflect both anticipated loads and travel speeds. A tire rated correctly for load at low speed may be overloaded at higher speed.
  • Maintain accurate service records to identify patterns of pressure loss, early wear, or recurring damage.
  • Train operators and maintenance teams to recognize visual indicators of improper inflation, such as shoulder wear (under-inflation) or center wear (over-inflation).

Conclusion

Proper tire inflation is more than a maintenance item—it is a performance strategy. By adhering to recommended pressure guidelines and adapting inflation levels with both speed and load conditions, operators can significantly extend tire life, improve safety margins, and reduce overall operating costs.