13 minute read
A fat performance for run-fat tires
from Modern Tire Dealer - August 2015
by EndeavorBusinessMedia-VehicleRepairGroup
Tire manufacturers say they hear ride and wear complaints loud and clear, and they’re making improvements
By Joy Kopcha
The standard complaints about run-fat tires that wear too quickly and offer an uncomfortable ride aren’t going away. In the last fve years as the replacement rate of non-run-fat tires on two-year-old cars has improved by 4%, the run-fat replacement rate hasn’t budged an inch.
Te annual survey by J.D. Power and Associates focuses on consumers who have replaced one or more tires during the frst two years of new-car ownership. Te replacement rate for run-fat tires is much higher than non-run-fats.
In 2011, the replacement rate for non-runfat tires was 20%. It dropped to 16% in 2015. In that same timespan, the replacement rate for run-fat tires remained 27%.
“We’ve seen the replacement rate for non-run-fat tires improve over the last fve years, but the replacement rate for run-fat tires has remained fat,” says Brent Gruber, who conducts the tire study and serves as director of the global automotive division for J.D. Power.
The faster-than-average replacement rates are problematic for tire manufacturers, A Bridgestone DriveGuard fact sheet shows the key components of run-fat tires. especially as car makers force run-fats to take hold of a larger piece of the overall tire market. Car makers BMW 550i, on a long road trip. Te car wasn’t equipped with see run-fats as one answer to their ongoing eforts to reduce a spare tire, and with damage to the sidewall, the owner was the weight of vehicles to meet new Corporate Average Fuel told not to drive on it. He waited on a fat-bed tow, spent a Economy (CAFE) standards by 2025. night in a hotel and was back on the road the next morning.
In 2014, run-fats made up 1% of the replacement passenger Turns out this was the frst of eight times his run-fats would tire market, with close to 2 million tires sold. go fat in less than 30,000 miles.
“It’s vital that auto and tire manufacturers address the Extraordinary experiences like that one aside, the future ride and wear issues, which are still not meeting customer of run-fat tires depends on improvements to ride and wear. expectations,” Gruber says. “Customers expect that run-fat So Modern Tire Dealer asked run-fat tire manufacturers tires won’t compromise tread life or the ability to provide a about consumer complaints and how they’re going to improve quiet and comfortable ride.” their tires to satisfy both features.
Te complaints about tire ride are especially strong among Here’s who responded to our questions: what J.D. Power calls the performance sport car category, whereas the dissatisfaction with tire wear is most prevalent Marco Verzino, director of quality, and Steve Carpino, with luxury car owners. vice president of research and development for Pirelli Tire
Tere are other concerns, however. Consumer Reports North America Inc.; recently highlighted the pain and sufering of one run-fat tire Lee Willard, tire engineer and Corvete tire specialist, owner who got a fat tire while driving his dream car, a 2012 Michelin North America Inc.;
Henry Kopacz, public relations and social media manager for Hankook Tire America Corp.;
Jay Robinson, general manager of brand marketing for Goodyear Tire & Rubber Co.;
Bob Liu, performance tires product manager for passenger and light truck tires at Continental Tire the Americas LLC; and
Robert Saul, director of consumer tire product strategy, Bridgestone Americas Tire Operations LLC.
Tire ride
Verzino and Carpino, Pirelli: Te number of ride complaints on run-fat tires has dropped dramatically from the early days, when the ride was admitedly harsh/stif. Te tire companies have made the tires beter for ride while maintaining the other required characteristics, while the vehicle manufacturers have goten beter at designing the suspension systems integrating the run-fat tire characteristics.
Willard, Michelin: Yes I’ve heard complaints on run-fat tire ride, but I’ve also heard more compliments on Michelin’s run-flat tire ride. Many consumers and even the OE test drivers that we work with can’t believe they are riding on a run-fat. Consumers interested in sporty handling almost never comment about comfort because they understand the relationship between ultimate handling control and comfort. Consumers only interested in a sof quiet ride should opt for standard radial tires to maximize these performances.
Vehicle manufacturers can greatly reduce the ride compromise
when they apply technologies like magnetorheological (MR) shocks. Tese shocks make the chassis very sof for normal driving comfort and make the chassis hard for sport handling to best work with the sporty tuned tires, including run-fats.
An asymmetric run-fat design addresses both the comfort needs and grip needs of UHP run-fat tires. (Willard created and Michelin acquired a patent for a tire “having asymmetrical self-supporting sidewalls” in 2010.)
Kopacz, Hankook: In the area of ride performance, Hankook focuses on designing an optimal sidewall profle that provides
Quik-Link: 800-687-1557 ext. 19114
the comfort consumers desire, while at the same time ofering run-fat capability. Designers also focus on carcass structure and raw materials to provide comfortable ride characteristics.
Robinson, Goodyear: Goodyear is always looking for ways to further improve the performance of its products based on the needs of our consumers. Tis has led to signifcant advancements in the area of ride comfort with each new generation of our run-fat technology.
Today’s Goodyear RunOnFlat tire technology enables our tires to ride similar to a conventional tire when infated, while still providing run-fat capability. Tis is especially true when the vehicle has been designed and tuned specifcally for the use of run-fat tires.
Liu, Continental: We do get a few consumer complaints regarding ride comfort for run-fat tires. Run-fat tires have stronger construction than standard tires to be able to support the vehicle weight even without air pressure for limited distances. Stronger construction typically leads to a less comfortable ride. Trough advanced engineering of new materials and contours along with careful tuning, the ride comfort of run-fat tires can be made to be close to standard tires.
Saul, Bridgestone: Many of the earlier generations of run-fat tires came out on sports cars where a frmer ride was more acceptable. We’ve worked really hard at Bridgestone to innovate new technologies that improve the ride comfort of run-fat tires.
Our third-generation run-fat technology, which is featured in the DriveGuard tire line, is specifcally designed to improve ride comfort. We continue to hear feedback from consumers and dealers who say Bridgestone DriveGuard tires ride like a touring tire, while also delivering the safety and peace-of-mind that you can only get from a run-fat tire.
Tire wear
Verzino and Carpino, Pirelli: We are improving tire wear like with any other tire: optimizing tire construction to target vehicle characteristics. Te overwhelming majority of our run-fat tires are OE tires, therefore made to meet the target requirements of OEMs.
Willard, Michelin: Michelin tire engineers apply computer analysis tools to optimize contact patch for wear characteristics of run-fat tires. (See spider chart below for improvements to the run-fat tires on the 2016 Corvete Z06.)
Kopacz, Hankook: Hankook focuses on developing run fat tires with a more consistent footprint shape for improved tread wear.
Robinson, Goodyear: Goodyear has continued to refne its RunOnFlat technology since the company frst pioneered the concept for commercial use more than 20 years ago. Our data today suggests the vast majority of consumers are satisfed with the wear rate of Goodyear RunOnFlat tires.
Liu, Continental: We continuously develop new technology for improving wear of all tires, including run-fats. Tread compounding, patern design, contour shape and construction all have infuence on wear.
Run-fat tires are not inherently diferent than standard tires except for construction, which afects comfort more than wear. Te main reason run-fats do not have a great reputation for
wear is that the vehicles with OE run-fats are typically tuned more for handling than wear.
Saul, Bridgestone: We know wear life is one of the top tire performance atributes that consumers want when they’re shopping for a new set of tires. We continually work across all of our product lines, including run-fat tires, to optimize our technologies and make sure that we deliver a tread wear performance that meets and exceeds the consumer’s expectations. Bridgestone’s new run-fat replacement tire line, DriveGuard, is backed by a 50,000 to 60,000 mileage tread wear warranty, which is improved over warranties on earlier generations of run-fat tires.
Marketing on safety
Despite their problems, the run-fat promise of not leaving a motorist stranded on the road is an efective selling point to consumers. Bridgestone’s DriveGuard tires have been on the market for a litle over a year, and the tire maker says that’s been long enough to hear from consumers who are praising the safety factor. One consumer wrote the company saying she “never felt so confdent about my safety with any other tire.”
Bridgestone is unique in its focus on consumers who want to shif from non-run-fat tires to run-fat products. Other manufacturers say the consumers asking about and buying their run-fat tires are ones replacing worn-out run-fat tires that came as OE.
“Most consumers purchasing our run-fat tires were satisfed with their OE run-fat tires and are purchasing replacements,” says Liu from Continental.
Potential for the future
Any growth of the run-fat market share is dependent on the car manufacturers. As their requests and ftments continue,
A BMW 328d at the New York International Auto Show, is outftted with Pirelli Cinturato P7 All Season run-fats.
the tire makers will follow.
Pirelli says pressure to improve fuel economy and free up space inside the vehicle will continue to drive development, and “there may be an increase in the usage in run-fat products.” Te company ofers 14 tire lines and 175 run-fat tire products in the U.S. “Tis allows vehicle manufacturers to get rid of the spare tire and jack. BMW is a major player while Mercedes Benz is increasing usage of run-fat products.”
Petlas Tire Corp. is just entering the run-fat game. Caglar Bahadir is in charge of development for consumer tires for the Turkish tire manufacturer, and says the tire maker introduced its frst run-fat tires during the third quarter of 2014 and is working to bring them to the United States.
“We are now into negotiations with several large size
Michelin makes and markets 20 types of run-fat tires, including these Pilot Sport Cup 2 tires on the 2015 Corvette. distributors from Tennessee, New York and Minnesota.” Te company also plans to open an ofce in the U.S. “very soon.”
“We are expanding our run-fat tires portfolio. By the end of this year we will have 22 new tire sizes to meet our customers’ demands. We think the run-fat tire market will continue to grow,” Bahadir says. “As more and more manufacturers improve their suspension systems in order to accommodate run-fat tires, complaints of harsh riding experiences are being eliminated day by day. Te safety and low fuel consumption run-fat tires ofer seems to eliminate the concerns of high costs. Te current increase in the run-fat tire sales globally is proof of this.”
Count Aeolus Tyre Co. Ltd. among the companies that’s investigated run-fat tire production. But Mike Leverington, general manager of Aeolus in the U.S., says run-fat tires have been, and remain, a top-tier tire product.
“Run-fat technology tends to be found more with the Tier 1 brands and top Tier 2 brands, all of which have at least some OE position in the global passenger tire business,” Leverington says. “But the additional cost at retail, the limited number of miles that can be driven and the harsher ride criticisms have made the run-fat segment limited and more of a niche concept rather than a broad line segment.”
Tose limitations make sales more difcult for lower tier tire manufacturers, Leverington says.
Te big question
If run-fats are the tires of the future, just how long do consumers, and their tire dealers, have to wait until the tires ride and wear like the non-run-fats on the road today?
Bridgestone DriveGuard tires are backed by a 60,000-mile warranty. Top ftments include the Toyoto Camry, Corolla and Prius, Honda Civic and Accord, Ford Fusion, Nissan Altima, Chevy Malibu and Cruze and the Volkswagen Jetta.
Te answer is: It depends.
Some tire makers say they’ve already hit the mark. “Tanks to our third-generation run-fat technology, Bridgestone has run-fat tires on the market today that ofer ride comfort and wear life that are comparable to conventional tires,” says Saul.
Even Gruber, the man who conducts the annual OE tire survey for J.D. Power, agrees. Teir surveys show some tire manufacturers are geting high marks for ride or wear. J.D. Power just won’t share those brand-related fndings because the manufacturers pay for that piece of the research. “As a total industry in the U.S. consumers place a great amount of emphasis on tire wear. Run-fat tire wear is an area where they are particularly defcient, particularly in the luxury vehicle segment,” Gruber says, “but there are some tire manufacturers who have optimized the run-fat tires to the point where those characteristics are not a deterrent, where satisfaction is comparable to non-run-fat tires.”
Pirelli says greater progress depends on the OE manufacturers and their expectations. “Te shorter the distance the tire is expected to be capable of operating without air, the smoother the ride will become overall.”
At Continental, Liu says the problem is in the comparison.
“If you compare apples to apples, run-fat tires wear like traditional run-fat tires today,” he says. “If you compare an OE sport performance run-fat tire on a vehicle with its alignment tuned for handing, to a standard touring tire on a vehicle with its alignment tuned for wear, there is a big discrepancy.
With those stifer sidewalls, Bahadir at Petlas says current run-fat tires won’t have the same comfort level as conventional tires. “But with developments by both tire and vehicle manufacturers, an average customer using run-fat tires on a vehicle designed for run-fats cannot distinguish the diference.” ■
