BFGoodrich hones self-inflating tire technology

GREENVILLE, S.C.—TPMS is a given these days, that small dashboard light that warns drivers of underinflated tires.

But what if that technology could do more than just offer insights? What if the technology could address the problem instead of just alerting to it? Michelin North America Inc. thinks it can.

The Greenville-based tire maker's BFGoodrich brand has developed and tested exactly that kind of technology, targeting it initially for off-road racing vehicles. Dubbed BFGoodrich ActivAir Central Tire Inflation System, it allows drivers to adjust the tire's PSI with the push a button.

"We were amazed at what the system could do," Harold Phillips, global general manager for BFGoodrich, told Rubber News. "It can deflate in about two minutes, and it is a little faster inflating. The speed of inflation and deflation depends on the size of the envelope of the tire."

The ActivAir system includes a compressor installed in the vehicle along with a control unit and control panel that Phillips said is the brains of the system.

Air lines go through the control unit to both the rear and front axles. Air is released through the lines to entry points at each wheel and then into the tires. There are four settings on the control panel: sand, rock, gravel and highway. Phillips added that more experienced drivers have the option to manually select their needed tire pressures.

"In the future," Phillips said, "The system will not have a control panel, it will instead be a plug-and-play option. Also, for the next-gen system we are working on a way for it to work without going through the axles, which are very expensive for the recreational off-roader to replace so they can add the ActivAir system."

The system is currently an add-on product, but the intention is to offer it as an original equipment option.

But when it came to developing and perfecting the technology, the off-road space offered the perfect opportunity.

"We selected the off-road racing market for testing because tire inflation is important for safety reasons and efficient use of the vehicles," Phillips said. "There are other off-road applications for the system, such as farming, ranching and mining. Police and military also need this type of safety and efficiency for their vehicles."

BFGoodrich prides itself on providing high-performance tires for customers who have a passion for driving in virtually any type of environment and most terrains. The company combines technical expertise with 50 years of motorsports to deliver tires for a full range of driving experiences, which range from ultra-performance street to off-road terrain, including mud, rock, sand and gravel.

The innovative, patented ActivAir technology was developed and tested by top builders in some of the most extreme environments, including the Dakar Rally and the Ultra4 Racing Series. The technology recently was awarded the 2023 Popular Science "Best of What's New" in Automotive. This is the fourth Michelin or BFGoodrich product to receive Popular Science recognition.

Several partners teamed up to make ActivAir a reality. And it all started with Teleflow.

The ActivAir Central Tire Inflation System was designed by Teleflow, and includes the latest generation of pneumatic valves with a display and control unit. ActivAir allows the transfer of all available power to the ground and maximizes traction. The driver chooses one of four operating terrains, and the system inflates or deflates the tires accordingly. More experienced drivers have the option to manually select desired pressures.

"Michelin purchased the Teleflow company in 2017," Phillips said. "The company was a French company that specialized in mobility solutions—namely CTIS—to regulate the inflation of tires on a vehicle."

Teleflow started by designing for the French military because of concern over the safety of soldiers having to exit their vehicles. Another liability was the tires on the military vehicles were susceptible to tire punctures from sharp objects.

"I started working with Teleflow in 2018," Phillips said. "I met with the company's president and was asked to help them come up with tire inflation solutions in North America based on my network in the United States military and for my passion and experience in the off-roading market.

"After looking at the Teleflow system I immediately saw an opportunity for the off-road market because tire inflation is such an important safety component for traction and durability. A system where the driver can deflate before going on the trail and then inflate when coming off the trail while the driver is actually driving the vehicle would be breakthrough technology for the off-road market space."

Phillips said that when vehicles like Jeeps are used for off-roading trails such as those at Rubicon, Moab or other off-roading trails, the drivers first air down their tires when getting to the trail according to the type of surface of the trail, such as gravel, sand or rock. Varying levels of inflation will help optimize the vehicle's traction and durability. And just as with the military trucks, off-road racers also battle with tires being more vulnerable to damage when hitting a sharp object such as rocks when the tire is fully inflated.

When a tire is deflated to the terrain, it is less likely to get damaged because the tire can envelop a rock more slowly. Sometimes the drivers are better at deflating than inflating when coming off the trail, which then creates more safety issues.

"One of the partners was the founder of Impulse Offroad and an off-road racer, John Williams. He was a key builder throughout the creation of ActivAir. He worked with BFGoodrich to integrate all components into several prototype vehicles to help test and create an innovative solution," Phillips said.

Another vital partner was Dynatrac, who had the expertise in integrating air passage in axle assemblies. The first prototype was built during the COVID-19 pandemic and was tested at the Moab off-road park. Right now, there are four vehicles with prototypes installed.

Beyond the off-road space, there are many potential applications for the ActivAir system, including Michelin's Connected Technologies.

"We are very involved in connected technologies, be it CTIS or tire pressure monitoring systems," Phillips said. "We believe the smart tire of the future will include technologies that will help our users improve the efficiency of overall mobility, and which regulation of tire pressure is a part of that. Michelin is also interested in other technologies such as tire sensors that would be able to measure the wear and tear of tires.

Another important sector for the ActivAir system is in the electric vehicle market. Phillips said tire inflation is important with EVs because driving on properly inflated tires can improve rolling resistance.

"Tire pressure has a place in EV because having optimal tire inflation can provide a better range for the EVs; it can also improve fuel efficiency," he said. "We haven't had the opportunity to test and gather data for it yet, but scientifically greenhouse gases and C02 emissions can also be improved by optimizing tire inflation."