What happens when you lose a tire on the road? You need a road service call for around $250 to $350. You may need a new tire for up to $500. But most important, you could lose a load of concrete. And if you don't make your delivery time, you may lose a customer. Between lost revenue and customer service, that can cost you thousands.
No one can guarantee you won't have a flat, but there are actions you can take to minimize the possibility of catastrophic tire failure.
Today's truck tires are very sophisticated devices designed primarily to hold air. There are as many as 20 or more individual components in a tire, from beads to radial cords and tread belts to inner seals.
All of the structure and various rubber compounds are designed to do two things. They keep the carefully engineered tread on the ground, and they keep air in the tire. The tread transfers forces to the ground for acceleration, braking, and cornering. The air supports the truck.
Air isn't just something to fill the tire. It's the reason the tire exists. Air is a critical, structural part of the truck.
Too much air, and tires become hard. They lose their ability to absorb shocks and to yield to rocks and objects that would cut, puncture, or abrade the tire. Excessive air pressure gives a harsh ride, damaging truck components and affecting driver comfort.
A tire can have too much air on a return trip from dropping a load. A tire properly inflated for 65 mph with a full load will be over-inflated on its return. Proper pressure is a function of speed and load. If the tire was 10% low for local use before departing, it could be critically low on the highway.
Far too many tires are under-inflated. A few years ago, the Federal Motor Carrier Safety Administration (FMCSA) checked pressure on 4000 tires over several weeks. They found more than 7% under-inflated by 20 psi or more. Only 44%—less than half—were within 5 psi of their target.
More important, fleets with 50 vehicles or less had more than 19% of all tires under-inflated by 20 psi or more, while fleets of 3000 or more had barely more than 2% similarly under-inflated. The difference is due to the more sophisticated maintenance practices of larger fleets, according to FMCSA.
When tire pressure is low, tread contact area elongates. That changes the rolling radius of the tire and increases the amount of flexing a tire experiences. It also causes sidewalls to flex. Excessive flexing consumes energy, deteriorating fuel economy. It also destroys tires. Here's how.
Have you ever flexed a paper clip? Move the wire back and forth and eventually it will break. If you touch the tips where it snaps, they'll be hot. A flexing tire can generate enough heat through internal friction to break wires in its steel cords and melt the rubber holding the tire together. That's why you will see thrown treads that litter the highways.