How to Read Tire Code: Complete Guide
Understanding tire codes is essential for maintaining your vehicle and ensuring safety. This comprehensive guide will teach you everything you need to know about reading tire codes.
Quick Summary
Tire codes contain important information including production date, size specifications, load capacity, and speed ratings. The DOT code indicates when your tire was manufactured, while size codes show dimensions and performance characteristics.
What is a Tire Code?
A tire code, also known as a DOT code or tire identification number, is a series of characters stamped on the sidewall of your tire. These codes are regulated by the Department of Transportation (DOT) and contain vital information about your tire's manufacturing details, specifications, and safety ratings.
Understanding these codes helps you:
- Determine when your tire was manufactured
- Know when to replace old tires
- Understand tire specifications and compatibility
- Make informed purchasing decisions
Step 1: Locate the Tire Code
Tire codes are typically found on the sidewall of your tire. Look for a series of characters that may include:
- Characters starting with "DOT" (Department of Transportation)
- A series of letters and numbers
- Manufacturer's name or brand
- Tire size specifications
💡 Tip:
The DOT code may be on only one side of the tire. If you don't see it on the outer sidewall, check the inner sidewall. Some tire manufacturers place it on both sides.
Step 2: Understanding DOT Codes
The DOT code is the most important part of a tire code for determining age. It typically looks like this:
DOT ABCD 4523Breaking down the DOT code:
- DOT: Department of Transportation identifier
- ABCD: Plant code and optional manufacturer information
- 4523: Production date code (last 4 digits)
Step 3: Reading the Production Date
The last four digits of the DOT code represent the production date. Here's how to read them:
Format: WWYY
WW = Week, YY = Year
Example: 4523 means week 45 of 2023
Important Notes
- • Week range: 01-52
- • Years 00-50 = 2000-2050
- • Years 51-99 = 1951-1999
⚠️ Safety Reminder
Tires older than 6-10 years should be replaced regardless of tread depth due to material degradation that can affect safety and performance.
Step 4: Understanding Tire Size Codes
Tire size codes provide information about the tire's dimensions and specifications. A typical tire size looks like this:
205/55R16 91V205 - Tire Width
Width in millimeters (205mm = 8.07 inches)
55 - Aspect Ratio
Sidewall height is 55% of the tire width
R - Construction Type
R = Radial (most common), B = Belted, D = Diagonal
16 - Rim Diameter
Rim diameter in inches
91 - Load Index
Maximum weight capacity (91 = 615 kg or 1,356 lbs)
V - Speed Rating
Maximum speed capability (V = 149 mph / 240 km/h)
Step 5: Load Index and Speed Ratings
Common Load Indexes
Common Speed Ratings
Frequently Asked Questions
Where exactly is the DOT code located?
The DOT code is stamped on the sidewall of the tire. It may appear on one or both sides. If you can't find it on the outer sidewall, check the inner sidewall (facing the vehicle).
What if my tire only has 3 digits instead of 4?
Tires manufactured before 2000 used 3-digit codes. The first 2 digits represent the week, and the last digit represents the year (0-9 = 1990-1999). If your tire has a 3-digit code, it's over 20 years old and should be replaced immediately.
Can I use our decoder tool to check my tire code?
Yes! Our free tire code decoder tool can instantly decode both DOT codes and tire size specifications. Simply enter your tire code and get detailed information about production dates, specifications, and safety recommendations.
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