Does Temperature Affect Tire Pressure?
In recalling some basic physics, we learn that a volume of gas will take up more space (increase) as the temperature increases; and conversely, the same volume of gas will take up less space (decrease) as the temperature decreases. Also consider that aside from outside weather temperatures, the tires in motion and machinery at work will also generate heat.
Two functions expected of industrial tires:
The first function is that the industrial tire (or any tire for that matter) is a container of air which provides the support for the weight distributed on top of the tire. In other words, it’s not so much the strength of the tire material that provides this weight support, but rather the volume of air inside the tire.
Also consider a second function and how it relates to air pressure. The tire is designed with tread patterns to offer the proper traction for job site surface conditions. Proper air pressure provides proper surface area contact when a tread-patch-area of the tire comes in contact with the construction site surface or road at any given moment during tire rotation. When heat causes the air pressure inside the tire to expand—that tread-patch-contact-area will become smaller—decreases—as the tire becomes over-inflated. This results in reduced traction, and ultimately affecting job performance along with uneven wear on the tires.
Conversely, colder temperatures will cause the tire to contract. With less air pressure to support the weight, the tread-patch-contact-area becomes larger—increases—as the tire becomes under-inflated (from weight pushing down on the tire). The tread-patch-contact-area spreads out more flatly on the job site surface or road. This spreading increases resistance as the tires rotates across the job site surfaces and ultimately contributes to reduced efficiency, increased fuel consumption, sidewall tire damage, and overall reduced life span of the tires and treads to name a few of the associated problems.
Best Practices for Fluctuating Temperatures on Tire Pressure
Always be aware of the proper inflation pressure recommended by the manufacturer and check pressures before sending the industrial and backhoe equipment out to an industrial job site. The best time to check tire pressure is when the tires have been cold—meaning that the equipment hasn’t been in use for several hours to avoid taking pressure readings during work times in which the tires may have had an opportunity to generate heat.
Significant Temperature Fluctuations
When there are significant temperature fluctuations, drivers can play a critical role in helping to maintain the correct inflation pressure. A good article by Bridgestone found here also offers some insights into the pros and cons of indirect vs direct TPMS technology—Tire Pressure Monitoring Systems—designed to automatically monitor tire air pressure. According to the article, and as one might surmise, the direct TPMS will be based on more reliable information data than the indirect TPMS.
Also keep in mind that the tire’s maximum inflation pressure may be different than the tire pressure used to rate the tire’s maximum load. The tire’s maximum inflation pressure is typically branded near the tire’s bead and is the highest “cold” inflation pressure that the tire is designed to contain. Recall that the “cold” condition is defined as early in the day before the outside temperatures heat up and before driving conditions cause the tire pressure to temporarily increase. Since it is normal to have mild fluctuations when the sun heats temperatures in the day as well as extensive driving of the equipment, it is NOT recommended to reduce the tire pressure during mild increases as the pressure will return to normal levels once the industrial tires return to “cold” (or inactive) conditions.
For more in-depth information, consult a tire specialist at Monster Tires
We are your nationwide leader in industrial tires, backhoe tires and industrial tracks. If you have any questions, feel free to give us a call anytime. We are always in the office and ready to answer any questions regarding tips for caring and prolonging the life of your industrial tires.