Flat Tire Repairs' Effect on Speed Rating(Lea en español)
How Slow Do You Have to Go?
The origin of tire speed ratings can be traced to Europe where they were needed to match high-speed tire durability with the unlimited vehicle speeds permitted on roadways like the German Autobahn. And even though the highest speed limit in the United States is 85 mph, speed-rated tires have become commonplace here due to the many vehicle models being sold globally.
Speed-rated tires use tire compounds able to withstand the anticipated speeds and add internal structural reinforcements to strengthen, stabilize and control the tire's shape as it rolls. Higher speeds require more capable compounds and stronger structural reinforcements.
Unfortunately, even the strongest compound or internal reinforcement can't prevent small screws, sharp nails or accident debris from piercing through the rubber compound and between the steel belts and fabric cords, leaving the driver with a slow leak or a flat tire. Now comes the need for repair, and this is where the tire manufacturers have different policies.
U.S. Tire Manufacturers Association (USTMA) Repair Policies
NOTE: Formerly known as: Rubber Manufacturers Association (RMA)
The USTMA is an industry association whose membership includes most major domestic and foreign manufacturers building and selling tires in the United States. The USTMA collectively establishes the foundation of industry policies, from which the tire manufacturers can specify their company's exact position.
The USTMA makes available training presentations and workshop posters to assist tire technicians with the steps necessary to properly repair tires. Each tire manufacturer specifies USTMA tire repair procedures must be followed precisely to have any tire repair deemed proper.
The USTMA's stand on puncture repairs is as follows:
|Industry Association||Speed Rating||Multiple Repair Locations|
|U.S. Tire Manufacturers Assoc.
|As per manufacturer||Repairs cannot overlap.
Some manufacturers specify
While USTMA establishes industry standards, their procedures are superseded by any policies and detailed instructions made by the tire manufacturers.
Tire Manufacturer Policies
A few tire manufacturers allow a punctured tire to retain its speed rating when returned to service if it can successfully pass a thorough exterior / interior inspection and be repaired following the U.S. Tire Manufacturers Association (USTMA) specified multi-step procedure.
Several other manufacturers specify their highest speed-rated tires (originally V-, Z-, W- or Y-speed rated) can be driven no faster than the 130 mph speeds permitted of a lower H-speed rating.
However, most tire manufacturers reason that since they have no control over the severity of the damage caused by the puncture, the destructive stresses encountered if the tire was driven while underinflated/flat or the quality of the repair itself, they cannot confirm if the tire has retained its full integrity or high-speed capability. Therefore, most tire manufacturers have established policies that a punctured and repaired tire no longer retains its speed rating and should be treated as a non-speed rated tire driven no faster than 85 mph.
Finally, a few tire manufacturers recommend outright tire replacement, as they will not accept repaired tires for warranty consideration or do not endorse repair of V-, Z-, W- or Y-speed rated tires.
A summary of tire manufacturer speed-rated tire repair policies for non-run-flat tires are listed below:
Tire Manufacturer's Puncture Repair Recommendations
|Manufacturer/Brand||Speed Rating||Multiple Repair Locations|
|BFGoodrich||Maintained||3 repairs, minimum 90° apart|
|Bridgestone||Voided||2 repairs, must be a minimum of 16" apart|
|Continental*||Maintained||Repairs cannot overlap|
|Cooper||Voided||Repairs cannot overlap|
|Dick Cepek||Voided||Repairs cannot overlap|
|Dunlop||Maintained**||Repairs cannot overlap|
|1 repair, H and above|
|Falken||Voided||Repairs cannot overlap|
|Firestone||Voided||2 repairs, must be a minimum of 16" apart|
|Fuzion||Voided||2 repairs, must be a minimum of 16" apart|
|General*||Maintained||Repairs cannot overlap|
|Goodyear||Maintained**||Repairs cannot overlap|
|1 repair, H and above|
|Hankook||Maintained||Repairs cannot overlap|
|Kumho||Voided||2 repairs, minimum 180° apart|
|Laufenn||Maintained||Repairs cannot overlap|
|Michelin||Maintained||3 repairs, minimum 90° apart|
|Nexen||Maintained||Repairs cannot overlap|
|Pirelli V and Above||Repair Not Endorsed by Pirelli||1 repair|
|H and Below||Maintained|
|Power King||Voided||Repairs cannot overlap|
|RIKEN||Maintained||3 repairs, minimum 90° apart|
|Sumitomo||Voided||Repairs cannot overlap|
|Toyo H and Above||Reduced to H. Voided if more than one repair.||4 repairs, minimum 90° apart|
|Below H||Maintained. Voided if more than one repair.||4 repairs, minimum 90° apart|
|Uniroyal||Maintained||3 repairs, minimum 90° apart*|
|Vredestein V and Above||Repair Not Endorsed by Vredestein||2 repairs|
|H and Below*||Reduce 1 speed rating per repair|
|Yokohama||Voided||Repairs cannot overlap|
|*Voids materials, workmanship and tread wear-out warranties.|
**Only 1 repair permitted to retain H and above speed ratings.
Tire manufacturers' policies for run-flat tire repair can be found here: Flat Tire Repairs - After Driving on Flat Run-Flat Tires