What Is Meant By Underinflation In Tires?
Underinflation in tires happens when a tire’s air pressure is below the recommended pressure. It can’t support the vehicle’s weight properly. This condition causes the tire to bend and flex too much, leading to heat buildup and damage. It also shifts the vehicle’s load to the tire’s outer edges, causing faster wear​​​​​​​​​​.
Signs of Underinflated Tires
- TPMS Warning: A tire pressure monitoring system (TPMS) alerts you when tire pressure is low.
- Flapping Noise When Driving: Underinflated tires make a noticeable flapping sound.
- Loss of Tire Shape: Tires appear flatter and lose shape.
- Reduced Steering Abilities: Steering becomes harder with underinflated tires.
- Increased Stopping Distance: It takes longer to stop the vehicle.
- Sidewall Cracks: Cracks develop faster on underinflated tires.
- Below Average Fuel Economy: Fuel efficiency drops as tire resistance increases.
- Vibrations: The car may vibrate or the steering wheel may shake​​​​​​​​​​​​.
Effects of Underinflation on Tires
Decreased Fuel Efficiency
Underinflated tires increase the rolling resistance of the vehicle. This means the engine must exert more effort to move the vehicle, leading to increased fuel consumption. The US Department of Energy notes that for every 1 psi drop in tire pressure, fuel efficiency decreases by 0.4%.
Uneven Tread Wear
Tires that are underinflated show more wear on the edges of the tread. This uneven wear reduces the lifespan of the tires and necessitates more frequent replacements.
Heat Build-up and Blowouts
Underinflation can lead to excessive heat build-up in the tires. This not only accelerates wear but can also cause tires to blow out entirely. The U.S. Highway Traffic Safety Administration assigns a temperature rating to tires under the assumption that they are properly inflated. Underinflation significantly reduces a tire’s ability to manage heat.
Reduced Load Carrying Capacity
Tires come with a tire-load rating, indicating the maximum weight they can bear. This rating is based on the tire being properly inflated. Underinflated tires cannot carry as much weight, which can affect the vehicle’s overall performance.
Handling and Maneuverability
Underinflation impairs the vehicle’s handling and maneuverability. It results in longer stopping distances, reduced traction, and an increased risk of skidding or hydroplaning, especially in adverse weather conditions. Properly inflated tires, in contrast, provide optimal grip and enhance the overall stability and control of the vehicle.
Is Underinflation a Major Cause of Tire Wear?
Yes, underinflation significantly affects tire wear. It can reduce tread life by up to 25%, requiring earlier tire replacement. It also increases the risk of tire blowouts and can damage the rims. The heat generated due to excessive bending of the tire edges can affect fuel efficiency too​​.
In What Conditions, Underinflation Is Necessary for Tires?
Underinflation is necessary in certain conditions, like driving in mud or on rocks. It increases the tire’s contact patch with the road and enhances traction on highly uneven surfaces.