Self-Inflating Tire Technology for Expediter Trucks
According to the U.S. Environmental Protection Agency, a tire that's underinflated by just 10 pounds per square inch (psi) can reduce fuel efficiency by up to 1 percent per tire.
That's because as a tire loses air, it flexes, increasing the surface area of the tire that touches the road, which generates greater friction. And that means the truck requires more energy – or fuel – to overcome the added road resistance.
The increased friction also builds up heat in the tire, leading to accelerated deterioration and higher risk of blowout.
And since tire pressure fluctuates in extreme temperatures, it can be difficult and often impractical for drivers to manually keep up with tire pressures all the time.
So, what if your truck's tires could maintain optimal pressure at all times, in any climate, all by themselves? What impact could self-inflating tire technology have on fuel economy, tire replacement intervals (and cost), driver safety, and uptime?
In 2010, two Stanford University mechanical engineering graduate students, Josh Carter and Brandon Richardson, launched Aperia Technologies in Burlingame, Calif., to find out the answers.
Today, Aperia's Halo self-inflating tire system, which recently won the 2014 Technical Achievement Award from the Truck Writers of North America (TWNA), is changing the way owner-operators and fleet owners keep the right amount of air in their tires.
Halo bolts onto the axle hub of the drive and trailer axles and uses a wheel's rotational motion to power an internal pump, similar to how a self-winding watch operates, to inflate and maintain optimal tire pressure.
Halo's fully mechanical design, which does not use electrical sensors and air compressors, helps minimize maintenance requirements and the overall weight of the system (which is roughly 6 pounds per unit).
What about installing Halo on the front (steer) axle?
The company says that it is working on a version of Halo for use on steer axles but that the current market demand (and business case) for self-inflating tire technology is much more robust for the drive and trailer axles.
"The data suggests that the steer tires suffer from under-inflation less than other wheel positions," says Josh Carter, Aperia's CEO. "Then there is also the practical aspect. In the drive and trailer positions, one Halo unit protects two tires per side of the truck. But in the steer position, you're protecting only one tire per side. So, there's more value for your money in the other wheel positions.
So, how much does Halo cost?
The base price is about $300 per unit, with cost variations based on options for brackets and hoses required for specific applications.
"We're working with each customer, with the application and their volume, to work out an overall specification and pricing package that works for them," says Carter.
For a tandem axle expediter straight truck, four Halo units would be required. A single axle expediter truck would use two units.
The company says that owner-operators can expect to recoup the cost of Halo through lower fuel costs, extended tire life, and reduced risk of downtime from blowouts.
How is Halo calibrated to maintain proper pressure for your truck's tires and application?
The tire pressure settings are calibrated at the factory by Aperia. "We'll will work with you and your tire vendor to determine that optimal pressure for your truck and application," says Carter.
What if, after using Halo for a while, you have a change in tire pressure requirements? How is the Halo recalibrated? Should you make that adjustment on your own?
"No. In the name of safety and liability, the owner-operator or fleet owner would ship it back to us," says Carter. "This way, we can make sure it's reconfigured accurately to protect our customers."
What's involved with installation? Can you install Halo yourself? Or, does Aperia recommend using an authorized installer?
Carter says that owner-operators can easily install Halo themselves, saying the process takes about 10 minutes and requires only a ratchet and an appropriate-size socket. He says Aperia also offers a video that walks you step-by-step through the installation process.
Where can expediters purchase Halo?
Expediters can order Halo directly through Aperia by going to www.aperiatech.com.
Although the technology is new, Aperia says the Halo units have undergone extensive heavy-duty fleet evaluations for over two years, with 8 million miles of on-road testing, including winters in Canada and summers in Florida. The company expects Halo to operate effectively for 500,000 miles or 10 years.