Rubber & Plastics News (subscription required) has details on a new consumer satisfaction survey from J.D. Power that indicates that owners of 2011- and 2012-model year cars in the US equipped with run-flat tires are less satisfied with their tires than owners of cars with standard tires. The findings are based on input from about 2,150 owners of cars with run-flats, about 7% of all respondents. Run-flats are installed primarily on luxury and performance sports cars and, while both groups were less satisfied with run-flats, the dissatisfaction was more pronounced among sports car drivers:
The difference in satisfaction level among owners of luxury vehicles vs. others was only about 1.5 percent, J.D. Power’s data show, while the difference among sports car owners was more than 9 percent.
The main complaint about run-flats was that they need to be replaced prematurely. According to the survey, 31% of customers with OE run-flat tires had to replace at least one tire in the first two years of ownership, compared to 19% for those whose vehicle was equipped with standard tires.
On May 17, Bridgestone announced the launch of its new Run-Flat Technology tire (RFT), the POTENZA S001 RFT, for the replacement market in the Middle East and Africa. The tires will be available beginning this summer in 16 different sizes, ranging from 16 to 19 inch diameters. Run-Flat Technology tires are designed to provide 80 km distance at 80 km per hour speed after deflation.
POTENZA S001 RFT tires are the latest generation of Bridgestone’s Run-Flat Technology tires, which were first launched in the early 1980s.
The main features of the new POTENZA S001 RFT are:
– The use of new side-wall reinforced rubber and COOLING FIN technology, both of which control heat, creating a comfortable ride comparable with POTENZA S001 (non RFT).
– It delivers high dimensional dry and wet performance like POTENZA S001.
– It is recommended for customers who demand Run-Flat Technology tires for a smoother ride.
Stuff (via the Sydney Morning Herald) has a piece on Michelin’s ongoing work on a self-repairing tires, an area in which Continental also is active.
The self-repairing tyre can be driven over nails without losing pressure, thanks to a new rubber compound that immediately plugs any holes in the tread.
The tyre is not the first to have self-healing properties – Continental launched similar technology in 2009 – but Michelin says early versions of self-repairing tyres struggled to deliver the same performance as undamaged tyres, with the compound sinking to the bottom of the tyre if a car was parked for any length of time. This would create vibrations and affect rolling resistance, increasing fuel use.
Tires based on the Michelin technology are not yet available, but the company insists that the tires will be superior to run-flats because they can be driven at normal speeds if they’re punctured and offer better ride comfort. Like run-flats, self-repairing tires offer the benefits of allowing carmakers to remove the spare, thus saving weight and space, and reducing vehicle weight.
Bob Ulrich at Modern Tire Dealer notes something that also caught my eye. More and more cars are eliminating their spare tire to save weight and space, but many are replacing them with inflator kits (and cell phones) rather than run-flats to compensate.
With the announcement that the 2011 Chevy Cruze is foregoing a spare tire in order to improve gas mileage comes a few comments about run-flat tires.
Did the Cruze come with them? I found it hard to believe it would, given its less-than-ultimate-driving-machine stature.
The answer? No, run-flat tires were not original equipment on the Cruze. It comes with an on-board tire inflator kit.
By shedding 26 pounds of tire and jacking hardware, the Cruze has an EPA-estimated 42 miles per gallon on the highway, “the best highway mileage of any non-hybrid, gasoline-fueled, compact available in the U.S. market,” according to General Motors Corp.
On Friday May 6, 2011, some seven years after first launching its SSR run-flat technology, Continental produced its ten millionth run-flat tire. The milestone tire was produced at the company’s passenger tire plant in Aachen, Germany – one of three million run-flats expected to be produced this year at the factory, which can produce a total of nine million passenger car tires per year, with a focus on high-end, specialized tires including high performance and ultrahigh performance. The SSR run-flat tires produced in Aachen are supplied to numerous OEM customers, including BMW, Ford Mercedes-Benz, Mini and Volvo.
Jon Crowley at Side x Side highlights an aftermarket run-flat systems for off-road ATV tires from GBC Motorsports. It’s called S.A.F.R.S. (Specialty Advanced Foam Run-Flat System).
This race track tested technology allows you to get back without damaging your tire or wheel. Its unique formula offers high heat resistance and a lighter more fuel efficient ride. SAFRS by GBC will run in any manufacturer’s tire, is easy to install and is a fraction of the cost of other popular systems.
Rita McGrath, blogging at Harvard Business Review, provides a short post-mortem on the failure of Michelin’s PAX run-flat tire system, which was discontinued in April 2008 after failing to catch on in the marketplace and prompting several class action lawsuits.
It turned out that to use the flat-run tires, the underbody of the cars had to be redesigned, and cash-squeezed auto makers proved reluctant to make the necessary investment. Also, replacing the tires required special equipment that most mechanic’s shops didn’t have and didn’t invest in. Say you had a flat-run tired and it failed, You’d have to go on a bit of a treasure-hunt to find someone who could replace it. Finally, if you did find a new PAX tire, it could cost upward of $1,200, about twice what customers expected to pay for a performance product.
Rita McGrath has written before on PAX, including this 2008 piece that includes many of the same points.
Earlier thoughts on the failure of PAX can be found here.
BMW of North America and Bridgestone Americas have settled a 2008 class-action lawsuit stemming from problems with the run-flat tires in 2006 and 2007 BMW 3-series models. The issue concerns the factory-installed Bridgestone Turanza EL42 run-flat tires, which exhibited irregular wear and excessive road noise and needed to be replaced early (before 30,000 miles). The class-action suit started with an owners’ group lawsuit that alleged BMW and Bridgestone should have known the tires were defective and prone to excessive noise and irregular wear. A federal court in New Jersey has accepted the settlement offer, clearing the way for affected BMW owners to apply for reimbursement. Bridgestone estimates the potential class at about 125,000 owners.
Under the terms of the agreement, members of the settlement class will receive a full refund for the purchase of replacement tires if they were needed before 10,000 miles. If replacement occurred between 10,000 miles up through 30,000 miles, reimbursement will be 50 percent or less.
More information is available at the RFT settlement website.
Coda Development, inventors of the Self Inflating Tire (SIT), which won Tire Technology of the Year award at the Tire Technology Awards for Innovation and Excellence 2009, in Hamburg, Germany, is looking for partners to commercialize the product, the company said in a March 19 press release. The company is looking for suitable partners with sufficient resources and know-how to finalize the R&D process and produce pre-production prototypes of the SIT to undergo on-road testing.
The SIT uses atmospheric air to inflate the tire automatically while the vehicle is in motion, compensating for natural loss of pressure, and ensuring constant tire pressure over the lifetime of a tire, according to the company. Primarily designed to aid fuel economy and safety, the system consists of two components: the tube chamber serving the function of a peristaltic pump for the tire, and a managing valve to control the inflation.
Details on the product are available here.
Bridgestone Corporation has announced the introduction of a “third-generation” run-flat tire for 2009, focusing on sales to original equipment manufacturers for installation in new passenger vehicles. Bridgestone is positioning the new run-flats as an environmentally-friendly option for OEMs to produce smaller, lighter, more fuel-efficient vehicles (by eliminating the space and weight associated with a spare tire). Bridgestone estimates that eliminating spare tires from all vehicles would reduce tire demand by 59 million units, thus lowering CO2 emissions by 2 million tons per year (encompassing the spare tire’s entire life-cycle, from raw materials procurement through disposal).
Bridgestone’s first generation of self-supporting run-flats were introduced in 1987. These tires tended to give a hard ride comparable to conventional tires because the sidewalls were thick and somewhat inflexible. In 2005, Bridgestone introduced its second generation run-flat tires, which featured an improved sidewall-reinforced rubber compound that created a softer ride. According to the company, the new third-generation RFTs achieve riding comfort comparable to conventional tires. Perhaps as importantly (from an adoption standpoint), the new tires will be available in a wider range of sizes, including sizes that were previously difficult to develop. Previous generations of self-supporting run-flats have been largely concentrated in high performance tires with very low aspect ratios.
Here is a link to the press release on the new tires, which is quite detailed and informative.