Tire Decision
07-26-2013, 10:11 PM
#46
I recently went with Dunlop Dierezza II's on all four concorners. Moving from Toyo Proxies. The Dlaps are quite sticky. I had them on for a track weekend and man what a difference in the level of grip. When they would loose grip it was nice, even and controllable. The street performance has also been good. At first they seemed a bit noisey. but after getting a few hundred miles on them, they have quiteted down. I would highly reccommend them.
07-26-2013, 10:43 PM
#47
Racer
Delete
07-26-2013, 10:45 PM
#48
Racer
Interesting. Rotate the rears with the Michelins? I have considered that myself but thought it was dangerous since I had heard anecdotally that the outside sidewall was stiffer than the inside. But I haven't found any conclusive evidence on that. When you rotated them did you notice any difference in handling?
07-26-2013, 11:13 PM
#49
Rennlist Member
Looks like the Europeans don't agree with the US manufacturers.
http://www.safetyresearch.net/safety-issues/tires/
Two independent studies in Germany, using different data sets, concluded that tires failed at a greater rate after six years and recommended manufacturers alert consumers in an effort to prevent potential crashes. In 1989, ADAC, Germany’s consumer advocacy counterpart to Consumers Union and AAA in the U.S., tested 23 unused spare tires ranging in age from five to 12 years old, in a high-speed bench test to determine the level of safety reserves over time. Although the test sample was small, the organization concluded: “Even tires that are just six years old – though they appear to be brand new – can present a safety risk. Tire experts even say that if they are not used, indeed, tires age more quickly.”
Overseas, the rubber industry’s acknowledgement of material degradation aging eventually evolved into the concept of an expiration date for tires. European and Japanese vehicle manufacturers including BMW, Audi, Volkswagen, Toyota, and later Mercedes-Benz, Nissan, and GM Europe, among others, included warnings to consumers in their owner’s manuals that tires older than six years should only be used in an emergency and replaced as soon as possible.
replaced as soon as possible.
Many of these warnings, which were added beginning in 1990, were also included in U.S. owner’s manuals. For example, GM’s European divisions Opel and Vauxhall added warnings to their owner’s manuals as early as 1991: “Tyres age even if they are used only very little or not at all. A spare wheel which has not been used for six years should be used only in emergencies; drive slowly when using such tyres.” Other warnings, such as those in Volkswagen’s 1992 owner’s manuals were more pointed: “WARNING – Tires age even if they are not being used. Tires which are older than 6 years old should only be used in an emergency and then with caution.”
In the U.S. it took the Ford Explorer/Firestone Wilderness ATX scandal to push tire aging to the front burner. In the 1990s, America’s most popular and best-selling SUV, the Ford Explorer, equipped with their original equipment Firestone tires, was prone to fatal rollovers after tread separations at highway speeds. The Firestone Radial ATX and Wilderness radial tires met all of the federal regulations at the time. Those standards, however, were written when bias-plies were the norm. There were no federal standards for occupant protection in rollovers and there was no minimum stability standard for Sport Utility Vehicles. Industry fought off any regulations, even as the rollover death tolls in light trucks rose to epidemic levels.
Then a series of gruesome high-profile crashes and news stories about the safety of Ford Explorers and Firestone tires triggered Congressional hearings. The Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in 2000 compelled NHTSA to re-write the tire standard and to examine tire aging. While the agency embarked on a tire-aging research and rulemaking, rubber manufacturers overseas were again translating their knowledge of tire aging into policy.
In June 2001, the British Rubber Manufacturers Association (BRMA), which represents the same tire manufacturers in the U.S. market, issued a recommended tire aging practice:
“BRMA members strongly recommend that unused tyres should not be put into service if they are over 6 years old and that all tyres should be replaced 10 years from the date of their manufacture.”
The recommendation noted that environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent could accelerate the aging process. Aging, the BRMA said could be identified by small cracks in the tire sidewall, however, “‘aging’ may not exhibit any external indications and, since there is no non-destructive test to assess the serviceability of a tyre, even an inspection carried out by a tyre expert may not reveal the extent of any deterioration.”
And yet, there was no such recommendation emanating from the Rubber Manufacturers Association in the U.S. Instead, the RMA was fighting NHTSA’s attempts to regulate tire age. In 2002, NHTSA proposed a tire aging test, only to be met with overwhelming industry opposition. The agency withheld further rulemaking and began additional research.
The Ford Motor Company, however, conducted its own research into the material science behind tire aging. Led by former 3M materials scientist Dr. John Baldwin, the Ford team conducted a methodical evaluation of thermo-oxidative aging and its effects on radial tires, and developed more precise tire age test methods. Ford’s conclusions, published in peer-reviewed journals, were based on a series of detailed analyses of field-aged tires. Baldwin’s team devised artificial aging techniques to replicate field aging, and tested tires to failure to determine the effects of age.
The National Highway Traffic Safety Administration (NHTSA) also tested and analyzed field-aged tires and reached similar conclusions in 2006. The American Society of Testing and Materials (ASTM) working group on tire age, which consists of tire, rubber, and vehicle manufacturer’s representatives, also replicated these findings.
The most significant data that links tire age to failures was cited in the August 2007, NHTSA’s Research Report to Congress on Tire Aging. In 2005, a provision in the Safe Accountable, Flexible and Efficient Transportation Equity Act required the agency to report to Congress by August 2007 on tire aging, including potential regulatory testing to evaluate the risk of failure after a tire has been aged. The agency reviewed insurance company tire claims reported from 2002 through 2006 and found 77 percent of the tire claims came from five hot-climate states (including California) and 84 percent of these claims were for tires more than six years old. This is the strongest published evidence to date of the link between tire age and tire failures.
And yet, this strong, contemporary research – following in the footsteps left by rubber material scientists more than three-quarters of a century before – have yet to translate into federal regulations, an industry consensus on policy and best practices or consumer or tire technician education. What the U.S. has seen is the slow spread of warnings in owner’s manuals and internal recommendations. In early 2005, Ford concluded that it needed to issue a 6-year replacement “recommendation” for tires, regardless of tread. The warning was placed on their website and appears in all of their 2006 owner’s manuals. DaimlerChrysler also added the 6-year warning.
In October 2005 Bridgestone/Firestone broke ranks with other tire makers and issued a “Technical Bulletin” to its dealers advising them that tires should be inspected after 5 years and replaced after 10 years – “even when tires appear to be usable from their external appearance or the tread depth may not have reached the minimum wear out.” Michelin and Continental issued similar bulletins in February 2006. Hankook joined the chorus in 2009. Most – including Bridgestone/Firestone – were actually recommending a 6-year shelf life for tires, because the tiremakers’ tire age warnings defaulted to the individual vehicle manufacturers’ recommendations. Automakers had, by and large, opted for a six-year tire age recommendation....
http://www.safetyresearch.net/safety-issues/tires/
Two independent studies in Germany, using different data sets, concluded that tires failed at a greater rate after six years and recommended manufacturers alert consumers in an effort to prevent potential crashes. In 1989, ADAC, Germany’s consumer advocacy counterpart to Consumers Union and AAA in the U.S., tested 23 unused spare tires ranging in age from five to 12 years old, in a high-speed bench test to determine the level of safety reserves over time. Although the test sample was small, the organization concluded: “Even tires that are just six years old – though they appear to be brand new – can present a safety risk. Tire experts even say that if they are not used, indeed, tires age more quickly.”
Overseas, the rubber industry’s acknowledgement of material degradation aging eventually evolved into the concept of an expiration date for tires. European and Japanese vehicle manufacturers including BMW, Audi, Volkswagen, Toyota, and later Mercedes-Benz, Nissan, and GM Europe, among others, included warnings to consumers in their owner’s manuals that tires older than six years should only be used in an emergency and replaced as soon as possible.
replaced as soon as possible.
Many of these warnings, which were added beginning in 1990, were also included in U.S. owner’s manuals. For example, GM’s European divisions Opel and Vauxhall added warnings to their owner’s manuals as early as 1991: “Tyres age even if they are used only very little or not at all. A spare wheel which has not been used for six years should be used only in emergencies; drive slowly when using such tyres.” Other warnings, such as those in Volkswagen’s 1992 owner’s manuals were more pointed: “WARNING – Tires age even if they are not being used. Tires which are older than 6 years old should only be used in an emergency and then with caution.”
In the U.S. it took the Ford Explorer/Firestone Wilderness ATX scandal to push tire aging to the front burner. In the 1990s, America’s most popular and best-selling SUV, the Ford Explorer, equipped with their original equipment Firestone tires, was prone to fatal rollovers after tread separations at highway speeds. The Firestone Radial ATX and Wilderness radial tires met all of the federal regulations at the time. Those standards, however, were written when bias-plies were the norm. There were no federal standards for occupant protection in rollovers and there was no minimum stability standard for Sport Utility Vehicles. Industry fought off any regulations, even as the rollover death tolls in light trucks rose to epidemic levels.
Then a series of gruesome high-profile crashes and news stories about the safety of Ford Explorers and Firestone tires triggered Congressional hearings. The Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in 2000 compelled NHTSA to re-write the tire standard and to examine tire aging. While the agency embarked on a tire-aging research and rulemaking, rubber manufacturers overseas were again translating their knowledge of tire aging into policy.
In June 2001, the British Rubber Manufacturers Association (BRMA), which represents the same tire manufacturers in the U.S. market, issued a recommended tire aging practice:
“BRMA members strongly recommend that unused tyres should not be put into service if they are over 6 years old and that all tyres should be replaced 10 years from the date of their manufacture.”
The recommendation noted that environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent could accelerate the aging process. Aging, the BRMA said could be identified by small cracks in the tire sidewall, however, “‘aging’ may not exhibit any external indications and, since there is no non-destructive test to assess the serviceability of a tyre, even an inspection carried out by a tyre expert may not reveal the extent of any deterioration.”
And yet, there was no such recommendation emanating from the Rubber Manufacturers Association in the U.S. Instead, the RMA was fighting NHTSA’s attempts to regulate tire age. In 2002, NHTSA proposed a tire aging test, only to be met with overwhelming industry opposition. The agency withheld further rulemaking and began additional research.
The Ford Motor Company, however, conducted its own research into the material science behind tire aging. Led by former 3M materials scientist Dr. John Baldwin, the Ford team conducted a methodical evaluation of thermo-oxidative aging and its effects on radial tires, and developed more precise tire age test methods. Ford’s conclusions, published in peer-reviewed journals, were based on a series of detailed analyses of field-aged tires. Baldwin’s team devised artificial aging techniques to replicate field aging, and tested tires to failure to determine the effects of age.
The National Highway Traffic Safety Administration (NHTSA) also tested and analyzed field-aged tires and reached similar conclusions in 2006. The American Society of Testing and Materials (ASTM) working group on tire age, which consists of tire, rubber, and vehicle manufacturer’s representatives, also replicated these findings.
The most significant data that links tire age to failures was cited in the August 2007, NHTSA’s Research Report to Congress on Tire Aging. In 2005, a provision in the Safe Accountable, Flexible and Efficient Transportation Equity Act required the agency to report to Congress by August 2007 on tire aging, including potential regulatory testing to evaluate the risk of failure after a tire has been aged. The agency reviewed insurance company tire claims reported from 2002 through 2006 and found 77 percent of the tire claims came from five hot-climate states (including California) and 84 percent of these claims were for tires more than six years old. This is the strongest published evidence to date of the link between tire age and tire failures.
And yet, this strong, contemporary research – following in the footsteps left by rubber material scientists more than three-quarters of a century before – have yet to translate into federal regulations, an industry consensus on policy and best practices or consumer or tire technician education. What the U.S. has seen is the slow spread of warnings in owner’s manuals and internal recommendations. In early 2005, Ford concluded that it needed to issue a 6-year replacement “recommendation” for tires, regardless of tread. The warning was placed on their website and appears in all of their 2006 owner’s manuals. DaimlerChrysler also added the 6-year warning.
In October 2005 Bridgestone/Firestone broke ranks with other tire makers and issued a “Technical Bulletin” to its dealers advising them that tires should be inspected after 5 years and replaced after 10 years – “even when tires appear to be usable from their external appearance or the tread depth may not have reached the minimum wear out.” Michelin and Continental issued similar bulletins in February 2006. Hankook joined the chorus in 2009. Most – including Bridgestone/Firestone – were actually recommending a 6-year shelf life for tires, because the tiremakers’ tire age warnings defaulted to the individual vehicle manufacturers’ recommendations. Automakers had, by and large, opted for a six-year tire age recommendation....
07-27-2013, 11:25 AM
#50
I did not notice any difference. It was interesting, when I had the tire rotated, they actually put the same tires back on in the same location. I had to get down on the ground with the manager to point out the tread wear difference on the inside. Fortunately, they did it correctly the next time and moved the left rear to left right side, keeping the rotation arrow in the proper direction. One of the reason I posted here was to see if there is an inside and outside difference to the Michelin that I missed the first time.
07-27-2013, 08:03 PM
#51
Racer
Just got the Pilot Sports today. They have inside outside but no rotation arrows. I must have had a different Michelin type in the past. Please disregard my prior post discussing rotation.
07-28-2013, 03:52 PM
#52
I ordered the Michelin tires today, as for the my Sumitomos the ride was not as good. More practically speaking, the Sumi's had a label inside and outside. There was no way to "rotate" the rears like I could with the Michelins. With the camber inner wear, I could switch left and right rear tires onto opposite side, but obviously had to remount on the other wheel. Michelins with "rotation" got better mileage.
07-28-2013, 04:42 PM
#53
Racer
07-31-2013, 02:07 AM
#54
Instructor
Join Date: May 2011
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check out the new bfg rival tread wear of 200 a bit sticker than PS2's should get same mileage on them. I went with toyo r888 in the rear awesome grip 100 on the tread wear BFG Rival's not available at that time. But will use them when it's time to replace them
07-31-2013, 10:18 AM
#55
11-08-2013, 04:48 PM
#56
3rd Gear
Join Date: Nov 2013
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Looks like the Europeans don't agree with the US manufacturers.
http://www.safetyresearch.net/safety-issues/tires/
Two independent studies in Germany, using different data sets, concluded that tires failed at a greater rate after six years and recommended manufacturers alert consumers in an effort to prevent potential crashes. In 1989, ADAC, Germany’s consumer advocacy counterpart to Consumers Union and AAA in the U.S., tested 23 unused spare tires ranging in age from five to 12 years old, in a high-speed bench test to determine the level of safety reserves over time. Although the test sample was small, the organization concluded: “Even tires that are just six years old – though they appear to be brand new – can present a safety risk. Tire experts even say that if they are not used, indeed, tires age more quickly.”
Overseas, the rubber industry’s acknowledgement of material degradation aging eventually evolved into the concept of an expiration date for tires. European and Japanese vehicle manufacturers including BMW, Audi, Volkswagen, Toyota, and later Mercedes-Benz, Nissan, and GM Europe, among others, included warnings to consumers in their owner’s manuals that tires older than six years should only be used in an emergency and replaced as soon as possible.
replaced as soon as possible.
Many of these warnings, which were added beginning in 1990, were also included in U.S. owner’s manuals. For example, GM’s European divisions Opel and Vauxhall added warnings to their owner’s manuals as early as 1991: “Tyres age even if they are used only very little or not at all. A spare wheel which has not been used for six years should be used only in emergencies; drive slowly when using such tyres.” Other warnings, such as those in Volkswagen’s 1992 owner’s manuals were more pointed: “WARNING – Tires age even if they are not being used. Tires which are older than 6 years old should only be used in an emergency and then with caution.”
In the U.S. it took the Ford Explorer/Firestone Wilderness ATX scandal to push tire aging to the front burner. In the 1990s, America’s most popular and best-selling SUV, the Ford Explorer, equipped with their original equipment Firestone tires, was prone to fatal rollovers after tread separations at highway speeds. The Firestone Radial ATX and Wilderness radial tires met all of the federal regulations at the time. Those standards, however, were written when bias-plies were the norm. There were no federal standards for occupant protection in rollovers and there was no minimum stability standard for Sport Utility Vehicles. Industry fought off any regulations, even as the rollover death tolls in light trucks rose to epidemic levels.
Then a series of gruesome high-profile crashes and news stories about the safety of Ford Explorers and Firestone tires triggered Congressional hearings. The Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in 2000 compelled NHTSA to re-write the tire standard and to examine tire aging. While the agency embarked on a tire-aging research and rulemaking, rubber manufacturers overseas were again translating their knowledge of tire aging into policy.
In June 2001, the British Rubber Manufacturers Association (BRMA), which represents the same tire manufacturers in the U.S. market, issued a recommended tire aging practice:
“BRMA members strongly recommend that unused tyres should not be put into service if they are over 6 years old and that all tyres should be replaced 10 years from the date of their manufacture.”
The recommendation noted that environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent could accelerate the aging process. Aging, the BRMA said could be identified by small cracks in the tire sidewall, however, “‘aging’ may not exhibit any external indications and, since there is no non-destructive test to assess the serviceability of a tyre, even an inspection carried out by a tyre expert may not reveal the extent of any deterioration.”
And yet, there was no such recommendation emanating from the Rubber Manufacturers Association in the U.S. Instead, the RMA was fighting NHTSA’s attempts to regulate tire age. In 2002, NHTSA proposed a tire aging test, only to be met with overwhelming industry opposition. The agency withheld further rulemaking and began additional research.
The Ford Motor Company, however, conducted its own research into the material science behind tire aging. Led by former 3M materials scientist Dr. John Baldwin, the Ford team conducted a methodical evaluation of thermo-oxidative aging and its effects on radial tires, and developed more precise tire age test methods. Ford’s conclusions, published in peer-reviewed journals, were based on a series of detailed analyses of field-aged tires. Baldwin’s team devised artificial aging techniques to replicate field aging, and tested tires to failure to determine the effects of age.
The National Highway Traffic Safety Administration (NHTSA) also tested and analyzed field-aged tires and reached similar conclusions in 2006. The American Society of Testing and Materials (ASTM) working group on tire age, which consists of tire, rubber, and vehicle manufacturer’s representatives, also replicated these findings.
The most significant data that links tire age to failures was cited in the August 2007, NHTSA’s Research Report to Congress on Tire Aging. In 2005, a provision in the Safe Accountable, Flexible and Efficient Transportation Equity Act required the agency to report to Congress by August 2007 on tire aging, including potential regulatory testing to evaluate the risk of failure after a tire has been aged. The agency reviewed insurance company tire claims reported from 2002 through 2006 and found 77 percent of the tire claims came from five hot-climate states (including California) and 84 percent of these claims were for tires more than six years old. This is the strongest published evidence to date of the link between tire age and tire failures.
And yet, this strong, contemporary research – following in the footsteps left by rubber material scientists more than three-quarters of a century before – have yet to translate into federal regulations, an industry consensus on policy and best practices or consumer or tire technician education. What the U.S. has seen is the slow spread of warnings in owner’s manuals and internal recommendations. In early 2005, Ford concluded that it needed to issue a 6-year replacement “recommendation” for tires, regardless of tread. The warning was placed on their website and appears in all of their 2006 owner’s manuals. DaimlerChrysler also added the 6-year warning.
In October 2005 Bridgestone/Firestone broke ranks with other tire makers and issued a “Technical Bulletin” to its dealers advising them that tires should be inspected after 5 years and replaced after 10 years – “even when tires appear to be usable from their external appearance or the tread depth may not have reached the minimum wear out.” Michelin and Continental issued similar bulletins in February 2006. Hankook joined the chorus in 2009. Most – including Bridgestone/Firestone – were actually recommending a 6-year shelf life for tires, because the tiremakers’ tire age warnings defaulted to the individual vehicle manufacturers’ recommendations. Automakers had, by and large, opted for a six-year tire age recommendation....
http://www.safetyresearch.net/safety-issues/tires/
Two independent studies in Germany, using different data sets, concluded that tires failed at a greater rate after six years and recommended manufacturers alert consumers in an effort to prevent potential crashes. In 1989, ADAC, Germany’s consumer advocacy counterpart to Consumers Union and AAA in the U.S., tested 23 unused spare tires ranging in age from five to 12 years old, in a high-speed bench test to determine the level of safety reserves over time. Although the test sample was small, the organization concluded: “Even tires that are just six years old – though they appear to be brand new – can present a safety risk. Tire experts even say that if they are not used, indeed, tires age more quickly.”
Overseas, the rubber industry’s acknowledgement of material degradation aging eventually evolved into the concept of an expiration date for tires. European and Japanese vehicle manufacturers including BMW, Audi, Volkswagen, Toyota, and later Mercedes-Benz, Nissan, and GM Europe, among others, included warnings to consumers in their owner’s manuals that tires older than six years should only be used in an emergency and replaced as soon as possible.
replaced as soon as possible.
Many of these warnings, which were added beginning in 1990, were also included in U.S. owner’s manuals. For example, GM’s European divisions Opel and Vauxhall added warnings to their owner’s manuals as early as 1991: “Tyres age even if they are used only very little or not at all. A spare wheel which has not been used for six years should be used only in emergencies; drive slowly when using such tyres.” Other warnings, such as those in Volkswagen’s 1992 owner’s manuals were more pointed: “WARNING – Tires age even if they are not being used. Tires which are older than 6 years old should only be used in an emergency and then with caution.”
In the U.S. it took the Ford Explorer/Firestone Wilderness ATX scandal to push tire aging to the front burner. In the 1990s, America’s most popular and best-selling SUV, the Ford Explorer, equipped with their original equipment Firestone tires, was prone to fatal rollovers after tread separations at highway speeds. The Firestone Radial ATX and Wilderness radial tires met all of the federal regulations at the time. Those standards, however, were written when bias-plies were the norm. There were no federal standards for occupant protection in rollovers and there was no minimum stability standard for Sport Utility Vehicles. Industry fought off any regulations, even as the rollover death tolls in light trucks rose to epidemic levels.
Then a series of gruesome high-profile crashes and news stories about the safety of Ford Explorers and Firestone tires triggered Congressional hearings. The Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in 2000 compelled NHTSA to re-write the tire standard and to examine tire aging. While the agency embarked on a tire-aging research and rulemaking, rubber manufacturers overseas were again translating their knowledge of tire aging into policy.
In June 2001, the British Rubber Manufacturers Association (BRMA), which represents the same tire manufacturers in the U.S. market, issued a recommended tire aging practice:
“BRMA members strongly recommend that unused tyres should not be put into service if they are over 6 years old and that all tyres should be replaced 10 years from the date of their manufacture.”
The recommendation noted that environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent could accelerate the aging process. Aging, the BRMA said could be identified by small cracks in the tire sidewall, however, “‘aging’ may not exhibit any external indications and, since there is no non-destructive test to assess the serviceability of a tyre, even an inspection carried out by a tyre expert may not reveal the extent of any deterioration.”
And yet, there was no such recommendation emanating from the Rubber Manufacturers Association in the U.S. Instead, the RMA was fighting NHTSA’s attempts to regulate tire age. In 2002, NHTSA proposed a tire aging test, only to be met with overwhelming industry opposition. The agency withheld further rulemaking and began additional research.
The Ford Motor Company, however, conducted its own research into the material science behind tire aging. Led by former 3M materials scientist Dr. John Baldwin, the Ford team conducted a methodical evaluation of thermo-oxidative aging and its effects on radial tires, and developed more precise tire age test methods. Ford’s conclusions, published in peer-reviewed journals, were based on a series of detailed analyses of field-aged tires. Baldwin’s team devised artificial aging techniques to replicate field aging, and tested tires to failure to determine the effects of age.
The National Highway Traffic Safety Administration (NHTSA) also tested and analyzed field-aged tires and reached similar conclusions in 2006. The American Society of Testing and Materials (ASTM) working group on tire age, which consists of tire, rubber, and vehicle manufacturer’s representatives, also replicated these findings.
The most significant data that links tire age to failures was cited in the August 2007, NHTSA’s Research Report to Congress on Tire Aging. In 2005, a provision in the Safe Accountable, Flexible and Efficient Transportation Equity Act required the agency to report to Congress by August 2007 on tire aging, including potential regulatory testing to evaluate the risk of failure after a tire has been aged. The agency reviewed insurance company tire claims reported from 2002 through 2006 and found 77 percent of the tire claims came from five hot-climate states (including California) and 84 percent of these claims were for tires more than six years old. This is the strongest published evidence to date of the link between tire age and tire failures.
And yet, this strong, contemporary research – following in the footsteps left by rubber material scientists more than three-quarters of a century before – have yet to translate into federal regulations, an industry consensus on policy and best practices or consumer or tire technician education. What the U.S. has seen is the slow spread of warnings in owner’s manuals and internal recommendations. In early 2005, Ford concluded that it needed to issue a 6-year replacement “recommendation” for tires, regardless of tread. The warning was placed on their website and appears in all of their 2006 owner’s manuals. DaimlerChrysler also added the 6-year warning.
In October 2005 Bridgestone/Firestone broke ranks with other tire makers and issued a “Technical Bulletin” to its dealers advising them that tires should be inspected after 5 years and replaced after 10 years – “even when tires appear to be usable from their external appearance or the tread depth may not have reached the minimum wear out.” Michelin and Continental issued similar bulletins in February 2006. Hankook joined the chorus in 2009. Most – including Bridgestone/Firestone – were actually recommending a 6-year shelf life for tires, because the tiremakers’ tire age warnings defaulted to the individual vehicle manufacturers’ recommendations. Automakers had, by and large, opted for a six-year tire age recommendation....