A main driver of change in the tire industry historically has been technology. Among the early technological advancements to tires were the introduction of carbon black into the rubber compound to provide more endurance and the development of synthetic rubber in 1937.
Other milestones include the development of the tubeless tire in 1947 and the introduction of steel-belted radial tire technology to the marketplace in 1948. Over the decades, such innovations have led to tires that today:
* Last tens of thousands of miles instead of a few hundred or a few thousand;
* Perform admirably under a wide variety of surface and weather conditions; and,
* Still, in many cases, cost significantly less relatively speaking than what customers paid for them a century ago.
And it seems technology will continue to drive change in the tire industry in the years ahead, as well.
Yes, tires likely will remain round and black, but they are increasingly being integrated with wheels, and even entire automotive systems. And in an effort to boost quality and uniformity while reducing manufacturing costs, several tire makers are perfecting and using automated production processes.
So what does the future hold?
NHTSA issues new tire safety standards
One of the most important drivers of near-term change will be the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act, signed into law in November 2001.
As part of this regulation, the National Highway Traffic Safety Administration (NHTSA) has issued new rules for tire makers, including updated tire standards for vehicles weighing less than 10,000 pounds. Bias-ply, small trailer, retreaded and non-pneumatic spare tires are exempted from Federal Motor Vehicle Safety Standard No. 139, which takes effect June 1, 2007, and updates FMVSS No. 109 issued 35 years ago. Additional rules governing commercial tires, both new and retreaded, also are under development.
Rule No. 139 differs from the old standard in that it imposes stricter requirements for high-speed and endurance tests and strengthens testing standards for limited-production snow and deep-tread tires. Guy Edington, managing director of Kumho Tire Co. Inc.'s North American Technical Center in Akron, maintains the TREAD Act ``is going to forever change the whole landscape of our business.'' Referring to the proposed standards, he predicted that ``if they are anything near what the government initially proposed-you're probably going to see a lot of your non-speed-rated tires, even S-speed rated, and maybe some of the T-rated go away.
``H-rated tires will become a staple in our industry to meet the proposed test requirements,'' he said. ``What that's going to mean is that customers will be paying a little more for their tires because there's going to be nylon reinforcement over the belts, a little more tire mass and so forth. But the tire will be able to sustain more speed because of these test requirements.''
Mr. Edington said he also believes the TREAD Act will require higher reserve loads in tires. Currently, the reserve tire load is specified at 12 percent of the vehicle's weight and the proposal is to go to 15 percent..
``Most metric tires carry about 3 percent more load than P-metric tires,'' he said. ``Most of them are one load index higher (than their P-metric equivalents). And I think the (auto makers) will see that as an opportunity to not have to upsize the tire.
``To get more load-carrying capacity you have to either get a bigger tire or one that carries more load. And a metric tire-say a 205/60R14-probably carries one more load index than a P205/60R14. If the auto manufacturer has to have a higher reserve load, all he has to do is replace that P-metric tire with a metric tire. That's by far the easiest thing to do. So I think you're going to see much lower use of P-metric tires because of the higher reserve load requirements of the TREAD Act.''
Patricia Brown, vice president, advertising and communications at Cooper Tire & Rubber Co., said she believes the largest impact of the legislation may be the effect of high-speed testing on light truck tires. ``This condition combined with the higher speed (75 mph requirement) on the endurance test is most likely to increase the speed ratings on tires and specifically light truck tires,'' she said.
``The impact of the combination of low-inflation-pressure and aging-effects requirements is not clear at this time since the final test procedures have not been developed, but they could likely require some tire design changes.'' She added that it is not likely that the requirements of the new FMVSS 139 regulation will cause changes in the maximum load and inflation pressure standards for current tire sizes.
TREAD Act testing standards for commercial truck tires still are under development at this time. David Laubie, executive director of engineering at Bridgestone/Firestone, said he believes standards for new and retreaded tires will be similar, if not the same, and that the same standards also will apply to drive- and steer-axle truck tires. ``NHTSA is hunting for a `one-test-fits-all' for drive, steer and retreaded tires,'' Mr. Laubie said. ``That's going to be tough, but that's what their goal is.''
Also under development with yet unknown ramifications are TREAD Act rules that cover commercial tire labeling, pressure monitoring and categorization and reporting of tire defects.
New styles and designs
Somewhat-but not entirely-removed from tire performance are the latest trends in passenger tire styling and tread patterns. Larger sizes, lower profiles, unidirectional and asymmetrical tread patterns are all gaining in popularity, and they contribute to vehicle appearance and performance.
``You're going to see more asymmetric tread designs going into more broad-line applications,'' said Kumho's Mr. Edington. ``Asymmetric is where performance tires are now. In the last 10 years, we've seen asymmetry going to light truck tires because it not only looks cool but also lets the designer do some things with the performance of the tire. It lets you improve handling while maintaining wear capabilities. It gives you, as the designer, a chance to better balance the performance.''
While new or different tread patterns are among the more visible changes being made to improve tire performance, they are certainly not the only ones. New materials are under development or in use for various tire components, as are new manufacturing methods aimed at providing greater integrity among those components.
Auto makers want lighter and quieter tires with lower rolling resistance and improved wet traction. The use of new materials, such as silica, in the tread compound is helping tire makers deliver these performance characteristics.
Cooper's Ms. Brown said one area of particular interest is in the compounds located farthest from the center of the mounted tire. Cooper is working on developing compounds that provide improved performance along with the benefits of reduced weight and/or volume. ``The key parameter tends to be more reinforcement with less material or weight,'' she said.
The use of precipitated silica instead of-or in combination with-carbon black as a reinforcing agent yields significant reductions in rolling resistance, and tire companies are accelerating their research and development in this field.
Michelin's so-called ``green'' tire is an example of a silica-based tread product. The company claims the development reduces rolling resistance by 35 percent compared with conventional tires and saves consumers 5 percent in fuel consumption.
Integrated tire and wheel systems
Tire makers long have dreamed of successfully developing and commercializing integrated tire and wheel systems, run-flat or extended mobility tires (EMT) and smart tires. And while progress has been made, the dreams have yet to be completely fulfilled.
Among the most commercially advanced of such systems is Michelin's Pax non-standard tire and wheel system.
``We continue to work on the Pax system,'' said Alison Heiser, former Michelin America's Small Tires (MAST) vice president of marketing. ``Pax hits two issues at the same time. It's such a different tire design that it allows the original equipment manufacturers to design the vehicle differently. Right now, the way tires and wheels are configured is a constraint to vehicle design. Pax really helps with this. Meanwhile, for consumers it has the continued mobility benefit which is achieved with an insert into the tire.''
David Van Emberg, director of product marketing for MAST, added that the Pax system provides performance benefits that go beyond the tire. He said Pax-which comprises a tire with short, strong sidewalls and ``inverted beads'' mechanically locked into a flat-base rim- reduces rolling resistance and improves handling and load capacity. Its integration with antilock braking systems allows for more effective stopping because there is more wheel and less tire, enabling larger brakes and suspension components for improved handling, he said.
Pax currently is available on the Audi A8 in Europe. In the U.S., the Pax system is on the Rolls Royce Phantom. According to Mr. Van Emberg, Michelin has produced more than 250,000 Pax assemblies. Pax also can be fitted on vans, sport-utility vehicles and other vehicles where run-flat tires will not work, he said.
There actually are three basic extended-mobility systems currently in development-the Pax integrated tire and wheel system; one that uses the existing drop-center rim with an internal support ring to keep the tire on the wheel; and another that uses self-supporting sidewalls. Several companies are dividing their run-flat eggs between at least two of these baskets.
Besides Michelin, those involved in the Pax development alliance are Goodyear, Hankook Tire Co. Ltd., Pirelli S.p.A. and Sumitomo Rubber Industries Ltd. Meanwhile, Bridgestone Corp., Continental A.G. and Yokohama Rubber Co. Ltd. favor staying with the existing drop-center rim and an internal support ring derived from Continental's Conti Safety Ring system already in use in Europe.
Goodyear, Pirelli, Bridgestone, Yokohama and Kumho also continue to develop their own reinforced-sidewall self-supporting designs. Michelin also continues to offer its own version of this concept, called Zero Pressure.
``We are a partner with Michelin in the Pax, but we also offer our own tire with a self-supporting sidewall that gives it run-flat performance under zero pressure,'' said J. Steven Carpino, director research and development for Pirelli Tire North America Inc., referring to the firm's ``PTM''-Pirelli Total Mobility-tire.
``Right now, that seems to be a better fit with some of the original equipment requests we've had. But it depends on the vehicle. In some cases, a self-supporting tire is a good solution,'' he said.
Bridgestone also is marketing a self-supporting run-flat tire, or SSR, which presently is on the Lexus SC430.
In addition to its joint venture with Michelin on the Pax system, Goodyear continues working with its own self-supporting sidewall EMT. Bill Hopkins, vice president of global planning and technology, said the company will make more than 800,000 run-flat tires this year, using automated production processes at three plants in Europe.
Goodyear's EMT is still, by volume, the most prevalent run-flat technology in the market, Mr. Hopkins said. Goodyear intends to support both technologies until an industry standard is established-and that could be a long time coming, he said. It will take at least until the end of this decade for run-flats to become established as OE tires because of vehicle design changes that are needed. By then, he predicted slightly fewer than half of all vehicles worldwide will use run-flats.
Alternatively, Michelin and Continental offer consumers self-sealing tires-which seal punctures in the tread area-in their Uniroyal Tiger Paw and General Gen*Seal brands, respectively.
Free-lance writer Chuck Slaybaugh contributed to this article.