Manufacturer's Certificate · 4440 ENU 64/204

911 (996) Manufacturer's Certificate 4440 ENU 64/204 • Tires that are stored unused for an extended period harden and become brittle faster than tires that are in continual use. • Hairline aging cracks can occur on older tires. • On tires in continual use, the kneading action activates the plasticizer in the rubber and thereby prevents hardening and cracking. • Therefore, attention should be paid not only to the tread depth but also to the age of the tire. • Tires should not be older than 6 years. • The age of the tire can be determined via the DOT code on the sidewall, which indicates the production date of the tire: e.g. DOT 2201= 22nd week of 2001. Important Notice: Technical Bulletins issued by Porsche Cars North America, Inc. are intended only for use by professional automotive technicians who have attended Porsche service training courses. They are written to inform those technicians of conditions that may occur on some Porsche vehicles, or to provide information that could assist in the proper servicing of a vehicle. Porsche special tools may be necessary in order to perform certain operations identified in these bulletins. Use of tools and procedures other than those Porsche recommends in these bulletins may be detrimental to the safe operation of your vehicle, and may endanger the people working on it. Properly trained Porsche technicians have the equipment, tools, safety instructions, and know-how to do the job properly and safely. Part numbers listed in these bulletins are for reference only. The work procedures updated electronically in the Porsche PIWIS diagnostic and testing device take precedence and, in the event of a discrepancy, the work procedures in the PIWIS Tester are the ones that must be followed. © 2021 Porsche Cars North America, Inc. Jul 30, 2021 Page 22 of 22 AfterSales