HILTON HEAD, S.C.—How intelligent can tires get?
Pretty darn intelligent, thanks to tire pressure monitoring systems and ongoing advances in run-flat tire technology, according to speakers at the 24th Annual Clemson University Tire Industry Conference.
By 2020, annual worldwide tire sales will rise to 2.3 billion units, compared with nearly 1.37 billion in 2000, and annual world truck tire miles will rise to 12 trillion from 2000's 8 trillion, according to William Hopkins, Goodyear vice president, technology and strategic initiatives.
New mandated information technologies such, as TPMS and Electronic Stability Control, obviously will have a tremendous impact on tires, as will fuel economy requirements and raw material prices, Hopkins said. Among other things, he noted 2020 is only 12 years away, and it takes seven years for a Hevea tree to mature.
“Tires are 80-percent petroleum by volume, and that's what's driving up tire prices,” Hopkins said. “Passing on the extra costs is easy in the aftermarket, but OE's a tougher business.”
Finding raw material substitutes will be crucial in the next few years, according to Hopkins.
“You can't plant a lot of rubber trees, and there are applications where you can't substitute synthetic rubber for natural rubber,” he said.
A lot of research is going on for substitutes from such sources as the desert shrub guayule, Hopkins said, as well as in nanocomposites and functionalized polymers. Nanocomposites, he said, are not as strange as they sound: “Carbon black is a nanocomposite when you look at it.”
Tire makers will have to work together to develop tire technology that provides added value to the average person, according to Hopkins.
“We will be challenged to get more and more retreadability out of a casing,” he said. Customers also will demand better mile¬age, shorter braking distances, reduced weight, re-¬ ¬duced noise, lower fuel consumption and higher load capacities.
“For 100 years, we didn't talk to each other,” he said. “Today, we have to be responsible global citizens.”
Hopkins touched on TPMS and run-flat technologies, subjects other spea¬k¬ers discussed in more detail.
The age of intelligent tires is upon us, and TPMS technology is evolving rapidly, according to Kevin Rohlwing, senior vice president of training for the Tire Industry Association.
Federal requirements for TPMS on passenger vehicles are technology-neutral, but systems that measure tire pressure directly are by far the most popular, according to Rohlwing. Audi, however, is bucking the trend with a new generation of indirect TPMS it has debuted on all its models, he said.
The Audi indirect system uses the tire itself as a sensor, according to Rohlwing.
“The nice part of indirect TPMS is that for vehicle manufacturers, it's much less expensive,” the speaker said.
“Also, in servicing the system, I don't have to do anything. I press a button and I'm done. I don't have to jump through hoops.”
Nevertheless, other auto makers are unlikely to adopt the Audi system, according to Rohlwing. All the tires using the system have to be tested separately, and for the Audi A6 alone there are 50 different sets. They must be tested under all applications and conditions, such as snow, rain, high temperature, mountains, concrete and asphalt, he said.
Tire costs rising
Between TPMS and the proliferation of tires with small sidewalls and large rim diameters, the cost of buying and maintaining tires is going through the roof, according to Rohlwing.
“Tires are getting smaller sidewalls and bigger rim diameters, which is not good news to my industry,” he said. “Those tires are notoriously difficult to handle, and it's easy to tear the beads.”
Tire prices have increased nearly 15 percent in the past two years, Rohlwing said. “We're not far away from $1,000 becoming the normal price for a set of new tires,” he said. We may be there already with a number of manufacturers.”
As TPMS sensor batteries fail and motorists are faced with the cost of replacing them, they're going to be looking for alternatives, according to Rohlwing.
“If tires can be manufactured with internal pressure sensors, they may become more cost-effective than the traditional approach as systems standardize within each vehicle manufacturer,” he said.
The word on run-flats
Run-flat tires are under increasing demand from original equipment customers that want to save weight and space in their vehicles.
However, customers have rebelled against them because of the difficulty and expense of servicing and repairing them.
Bridgestone, however, is about to change that through its new “cooling fin” sidewall technology for run-flats, according to Kurt Berger, consumer products engineer with Bridgestone/Firestone.
High running temperatures have been the problem with run-flat tires, limiting their durability and their applications, according to Berger.
But with Bridgestone's cooling fin technology, he said, run-flat technology can be extended to vehicles with higher loads and higher-profile sidewalls, such as SUVs and trucks.
The new technology consists of fins on the tire surface, the design parameters of which are optimized to maximize convective heat transfer, the BFS executive said. The fins cool down the tires and enhance their durability.