What does DOT code 3321 mean?

DOT code 3321 indicates the tire was manufactured during week 33 of 2021 (August). This tire is approximately 5.0 years old.

Is a 5.0-year-old tire safe to drive on?

A 5.0-year-old tire has a safety index score of 50%. The tire is entering mid-life aging; regular sidewall inspections are advised.

Will DOT 3321 pass vehicle safety inspection?

A tire stamped DOT 3321 will pass annual vehicle inspections provided tread depth exceeds 1.6mm (2/32") and no visible sidewall bulges or deep cracks are present. However, compound hardening at 5.0 years affects wet stopping distance.

Where is the 4-digit DOT date code located?

The 4-digit DOT date code is stamped on the outer sidewall of the tire, immediately following the letters "DOT" and manufacturer plant codes.

🇺🇸 US DOT BATCH REPORTMODERATE AGING / INSPECTSERIAL REF: #3321

BATCH TELEMETRY:
DOT SERIAL 3321

This technical telemetry report examines tire production batch 3321, manufactured during the 33th week of 2021 (August). Operating at a calculated age of 5.0 years, the structural integrity and polymer elasticity of this serial series have been evaluated against NHTSA and NASCAR safety benchmarks.

PIT TIRE SAFETY INDEXINSPECT SIDEWALLS

61%MODERATE RISK

CALCULATED AGE5.0 Years

MANUFACTUREDWK 33, 2021

Pit Assessment: Rubber is entering mid-life aging. Inspect sidewalls for micro-cracks and check tread depth.

Manufacture Date

W33 / 2021

August Batch Output

Compound Age

5.0 Years

Natural Vulcanization Progress

Safety Index

50%

Moderate Risk Category

PIT CREW CHIEF VERDICT

"Stamped with serial 3321 (August 2021), this tire is entering its mid-life phase at 5.0 years of age. While functional with sufficient tread, natural atmospheric oxidation has initiated plasticizer evaporation. Sidewall flexibility is reduced."

Estimated Wet Braking Impact+8% to +15% Wet Braking Distance

Pit Crew RecommendationRegular sidewall micro-crack inspections advised every 3,000 miles.

REGULATORY GRADING FRAMEWORK

STANDARDIZED LABELLING METRICS

Cross-reference batch age with standardized grading for rolling resistance, wet grip index, and pass-by exterior noise.

REGULATION (EU) 2020/740 COMPLIANT

European Union Tire Label Metrics

⛽ Fuel EfficiencyISO 28580

CActive

7.8 - 9.0 kg/t (Standard efficiency)

Grade ScoreClass C

🌧️ Wet Grip SafetyISO 23671

BActive

1.40 - 1.54 (High wet grip)

Grade ScoreClass B

🔊 Exterior NoiseUNECE R117

71dB

Moderate (Complies with EU limits)

Noise ClassClass 2

FIELD GUIDANCE & TRACK SCENARIOS

REAL-WORLD IMPLICATIONS FOR DOT 3321

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INSPECTING USED VEHICLES

If inspecting a pre-owned vehicle fitted with DOT 3321 tires, note that you are looking at rubber manufactured 5.0 years ago. These tires are within their safe usable lifespan, provided tread depth exceeds 3mm.

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TRUNK SPARE TIRE ASSESSMENT

Found DOT 3321 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.

← DECODE ANOTHER DOT CODEBatch #3321 US DOT Telemetry Record