Tire Longevity - Why the Trucker’s World Revolves Around Tires
No one cares more about tires than truckers. They are one of the highest cost centers in truck maintenance, a major determinant of fuel efficiency, one of truckers’ greatest safety considerations, and a top target for DOT violations annually.
Tires matter very much. Understanding them, maintaining them and monitoring them should be a top priority for truckers, fleet owners and technicians alike.
The plain fact that they’re expensive—$500 apiece on average—begs the question: how many miles can you expect out of them?
How long do semi-truck tires last? Much hinges on the answer
The short answer in the trucking community and tire manufacturing world is 3 – 6 years, however mileage estimates are hard. Fleet Equipment Magazine says that the exact same tire could last for 200,000 miles in a line haul operation and only 75,000 doing pick-up and delivery runs.
The lifecycle of a truck tire depends on many factors, starting with the quality of the tires you buy. The application plays a role, too. Heavy long hauls or local driving with lots of stops and starts? Choosing the wrong tire shortens lifespan. Excessive torque accelerates wear as well as damage from road hazards or accidents.
Considering all this, perhaps the best answer to the question is that if you understand how to take care of your tires, not only will they last longer, but they’ll also save you more money on fuel, keep you safer, need replacing less often and just ride better.
How truck tires are constructed—the basics
In tires commonly used on semi-trucks, seven main layers work together to maximize flexibility, mileage, safe operation and resilience. Starting from the innermost layer, they are:
Inner Liner. It maintains air pressure and prevents deflation and blow outs. Usually made of synthetic rubber.
Carcass Ply. Made of fiber cords that bond to the inner layer rubber for strength. Specially constructed to restrain pressure from heavy loads.
Bead. This layer uses rubber, wire and steel to hold the tire on the rim.
Sidewall. This area between the tread and the bead protects the inner layers of the tire from side impact while providing flexibility.
Belts. Positioned between the carcass ply and the tread, this layer connects and reinforces these layers using rubber and steel cords bonded together.
Cap Ply. Usually made from heat-preventing polyester, this layer right under the tread helps control heat from friction caused at high speeds. In doing so it helps tires keep their shape.
Tread. The thickest, outermost layer. Like the rest of the tire, treads are designed for the application. Treads vary in depth, groove shape and rubber composition—hard for durability and fuel efficiency, soft for greater traction and smoother ride.
Different wheel positions use different tires
18 wheelers use three different types of tires. There are all-purpose tires, but it’s common practice to buy specific tire-types for each of the three wheel positions. Steer wheels emphasize traction, precision and strength to steer the truck. Drive tires, located behind the steer wheels of the tractor, are the power transmitters. They have strong treads to grip the road and maximize the power of the tractor. Trailer tires bear the load and often take abuse, making durability and protective sidewalls important features.
How to properly maintain commercial tires
Although one might think tires, being mostly made of rubber, should be able to take care of themselves, there is a lot drivers can and should do to make them last.
Maintain proper tire pressure. According to Tire Review magazine, tires typically lose up to 2% of their air pressure every month, and a tire that is underinflated by as little as 2% can exhibit irregular wear and other tire issues.
Match your tires. This is a given with the steer tires for safety reasons. For drive tires and trailer tires used in dual positions (side-by-side), ensure tires match to prevent unnecessary wear. Using tires from different brands or of different levels of wear means weight is unevenly distributed. Even using tires with different levels of inflation can cause a mismatch.
Check alignment. Prevent scrubbing and irregular tire wear by checking the alignment of your steer and trailer axles.
Fix mechanical issues. On a truck, one mechanical issue tends to affect the next and tires often bear the brunt. When things like U-bolts come loose, ball joints wear down and wheel bearings go bad, uneven tire wear can result.
Keep your tires balanced: Tires that are out of balance wear unevenly—and they are unsafe.
Rotate: A good rule of thumb is to rotate halfway or a quarter of the way through the expected mileage of the tire. Another way to gauge when to rotate is when tread depth measurements differ by 3/32 or more.
Do a daily walkaround. Not only is it good tire maintenance practice, it’s the law as part of the driver vehicle inspection report. Look for cuts or bulges and check the inflation, valve caps and tread wear.
Know when your tire’s time is up
The law states that tires with a tread depth less than 2/32” need to be replaced. To measure, use the penny test. Slide a penny into the tread of your tires with Lincoln’s head upside down and facing toward you. If you can see the top of his head, your tire has less than 2/32” of tread. Aging is also a factor. Many tire manufacturers recommend replacing tires after six years regardless of wear.
Key Considerations for Semi Trailer Tires
Semi trailer tires require special considerations because of the opportunities to save—both on the price of tires and on the resulting fuel economy.
Tread depth. Tires designed with deeper treads last longer. The tradeoff is that lower treads can have higher fuel efficiency, according to Heavy Duty Trucking.
Fuel efficiency. Semi-truck tires in general directly contribute to fuel consumption by about 35%, and trailer tires account for 42.5% of that figure, says Fleet Equipment magazine. For this reason, rolling resistance rating should be a key consideration in choosing trailer tires.
Trailer type. Trailer types wear on tires differently. For example, spread axle trailers tend to wear down tires faster than standard axles.
Driving distance. For long haul driving, extended wear tires with a high rolling resistance rating can be a long lasting, fuel-maximizing choice. For regional deliveries, tires with a thick tread and durable sidewalls will withstand hazards and urban abuse better and last longer.
Using used tires. Drive and steer tires can be moved to the trailer after they wear down. It’s a way to squeeze a few more miles out of tires before they’re retired.
Retreads. Retread tires are used tires that have been resurfaced. They can be a cost-effective option for trailers. 44% of all commercial tires on the road in the U.S. and Canada are retreads.
Take Tires for Granted at Your Own Peril
Failing to maintain or properly attend to tires has significant consequences.
Tires are a leading contributor to maintenance and repair costs. Tires, tubes, liners and valves make up 43 percent of the top-ten M&R costs to operate a Class 8 truck, WasteAdvantage magazine says. It pays to carefully consider purchase and maintenance decisions.
It pays from a safety perspective, too. 38.2% of crashes involving vehicle defects were tire/wheel-related per 2020 Pennsylvania Crash Facts & Statistics produced by Pennsylvania Department of Transportation.
Do you have everything you need to perform tire repair and maintenance? Imperial Supplies can set your shop up for success. Talk to one of our reps today