This technical telemetry report examines tire production batch 4520, manufactured during the 45th week of 2020 (November). Operating at a calculated age of 5.8 years, the structural integrity and polymer elasticity of this serial series have been evaluated against NHTSA and NASCAR safety benchmarks.
Pit Assessment: Rubber is entering mid-life aging. Inspect sidewalls for micro-cracks and check tread depth.
"Stamped with serial 4520 (November 2020), this tire is entering its mid-life phase at 5.8 years of age. While functional with sufficient tread, natural atmospheric oxidation has initiated plasticizer evaporation. Sidewall flexibility is reduced."
Cross-reference batch age with standardized grading for rolling resistance, wet grip index, and pass-by exterior noise.
If inspecting a pre-owned vehicle fitted with DOT 4520 tires, note that you are looking at rubber manufactured 5.8 years ago. Because the rubber compound has hardened, request a tire replacement credit or discount from the seller.
Found DOT 4520 on your emergency spare? Unused rubber still oxidizes due to ambient temperature swings and ozone in the trunk. This spare remains safe for standard emergency highway use.