Tire Pressure When It Is Too Cold

Fight Cold Weather Tire PSI Loss

Cold weather can negatively affect the performance of trucks on the road including a decrease in fuel mileage. But what truck drivers may not consider is how the cold weather affects tire pressure. Proactive tire maintenance is a must for combating the harsh winter climate. Here's what drivers need to know about cold weather and tire PSI.

Let's Talk Nerdy

Changes in air temperature affect the speed of air molecules in a tire thus resulting in a fluctuation of tire inflation pressure. If a truck is thumping, it could be the loss of tire pressure due to drastic changes in air temperatures (cold air). However, hot tires can also impact the pressure of a tire as well as the sound. While truck drivers may be able to eye one low tire from another, they will never be able to determine the exact pressure rating for each tire just by looking at them.

Driving With Underinflated Tires

The U.S. Department of Transportation (DOT) has mandatory minimum requirements for tread depth on all commercial vehicles, 4/32-in. for the steer tire position and 2/32-in. in all other positions to ensure commercial truck tires have the appropriate level of tread for operation (Fleet Owner, Proactive maintenance will help your tires survive winter).

According to a 2014 interview in Overdrive with William Estupinan, VP of technical service for Giti Tire, running a tire underinflated by 20 percent can reduce tire tread life by 30 percent. He went on to say running tires underinflated at 40 percent will reduce tire life by 50 percent. Lastly, every 10 percent of underinflation can cause a 1 percent reduction in fuel economy. "That's not to mention factors like irregular wear, higher thermal and mechanical fatigue of the casing, lower retreadability and even premature failure," Estupinan says.

Hazardous Road Conditions

In some cases, it can be wise to drive with a lower air pressure such as in snow or ice. This move can increase traction-control – just be sure to adjust tire PSI after bad weather.

Right PSI For Semi Trucks

The numbers are up for debate within the trucking industry; however, the consensus in the trucking community is that tire pressure depends on the truck and maximum load capacity. The right PSI for semi-truck tires will also depend on several factors including: Whether they are "steer" or "drive" tires, the brand of tires, and the size of the tires. Typically, heavy-duty steer tire pressure should be at approximately 110 PSI while drive tire pressure can set around 85 PSI. All PSI will be different based on application.

Checking Tire Pressure

Use a tire pressure gauge to easily determine tire PSI – the process only takes a few minutes. This will help determine underinflation or overinflation. Remember, the drop in temperatures will only be an issue if tires are underinflated.

Final Thought

Driving with low air pressure in wintry conditions can increase traction but decrease fuel economy. If driving through snow and ice, it can be a good idea to lower PSI then adjust it when roads are not in hazardous conditions.