Skip to content Skip to footer

Understanding Tire Numbers and Codes: What They Mean in Canada

Tires are more than just round rubber parts that keep your vehicle rolling — they are complex products designed with specific measurements, safety standards, and codes. If you’ve ever looked closely at your tire’s sidewall, you’ve probably seen a combination of numbers and letters. But what do they actually mean?

In this article, we’ll break down tire numbers and codes, explain their meaning, and give you real examples — especially those common and standard in the Canadian market.

Why Tire Codes Matter

Understanding tire numbers and codes helps you:

  • Choose the right replacement tire
  • Drive safely in Canadian weather conditions
  • Ensure proper load capacity and performance
  • Comply with legal and manufacturer specifications

Breaking Down the Tire Code: Example and Meaning

Let’s start with a typical tire code you might see on the sidewall:

Example: P225/65R17 102T

Each part has a specific meaning:

CodeMeaning
PTire type (P = Passenger vehicle)
225Tire width in millimeters
65Aspect ratio (height as % of width)
RRadial construction
17Rim diameter in inches
102Load index
TSpeed rating

Let’s go through these in detail.

1. Tire Type Code

  • P = Passenger vehicle tire (standard for cars, minivans, SUVs)
  • LT = Light Truck tire (for heavier loads)
  • T = Temporary (spare tires)
  • ST = Special Trailer

In Canada, P-metric tires are the most common for personal vehicles.

2. Tire Width (e.g., 225)

  • Measured in millimeters
  • Indicates the width from sidewall to sidewall
  • Common sizes in Canada: 205, 215, 225, 235, 245

3. Aspect Ratio (e.g., 65)

  • Represents the sidewall height as a percentage of the tire width
  • A lower number = lower profile (better handling)
  • A higher number = more sidewall = smoother ride

For example:

  • 65 means sidewall height is 65% of 225mm → 146.25 mm

4. Tire Construction (R)

  • R = Radial (used in 99% of modern tires)
  • D = Diagonal (bias-ply, rare today)

5. Rim Diameter (e.g., 17)

  • Size of the wheel the tire fits
  • Measured in inches
  • Common rim sizes in Canada: 15″, 16″, 17″, 18″, 20″

6. Load Index (e.g., 102)

  • Indicates how much weight the tire can support
  • You can look up the number on a load index chart
Load IndexMax Load (kg)
91615 kg
95690 kg
100800 kg
102850 kg
104900 kg

For example, 102 = 850 kg per tire, or 3,400 kg total for 4 tires

7. Speed Rating (e.g., T)

Indicates the maximum speed capability of the tire.

Speed RatingMax Speed (km/h)Common Use
S180Family cars
T190Sedans, SUVs
H210Sports cars
V240High-performance
W270Luxury/performance

In Canada, T and H rated tires are very common for everyday vehicles.

Other Important Tire Markings in Canada

DOT Code

Example: DOT 4B08 ABC 0923

  • Shows the manufacturer, plant code, and date
  • Last four digits indicate the manufacture date
    • 0923 = 9th week of 2023

Always check this for tire age – tires older than 6 years should usually be replaced.

M+S and 3PMSF (Three-Peak Mountain Snowflake)

  • M+S: Mud and Snow – minimum all-season traction
  • 3PMSF: Certified for severe winter conditions (mandatory in Quebec from Dec 1 to Mar 15)

If you drive in Quebec, Ontario, Alberta, or any snowy province, look for the 3PMSF symbol for legal compliance and safety.

XL (Extra Load) or SL (Standard Load)

  • XL = Can handle higher air pressure and load
  • SL = Standard load capacity

If your vehicle manual says “XL required,” don’t downgrade to SL.

Common Tire Sizes in Canada

Here are examples of tire codes often seen in Canada:

Size CodeCommon Vehicle Type
P205/55R16 91HToyota Corolla, Honda Civic
P225/65R17 102TFord Escape, Toyota RAV4
LT245/75R16 120RFord F-150, Ram 1500
P215/60R16 94TNissan Altima, Mazda 6
P235/55R18 100HHyundai Santa Fe, Subaru Outback

Conclusion

Understanding your tire’s numbers and codes isn’t just for mechanics — it’s essential for every driver in Canada. These codes reveal everything from tire size and performance to safety and seasonal usage.

Before buying new tires or switching between all-season and winter tires, make sure you:

✅ Check your car manual
✅ Read your current tire sidewall
✅ Match the load index and speed rating
✅ Look for Canadian winter tire symbols if needed

FAQ

Q: Can I replace a tire with a different speed rating?
A: You can go higher, but never lower than what your manufacturer recommends.

Q: Are American tire codes valid in Canada?
A: Yes, but ensure the tire meets Transport Canada and winter tire requirements for your province.

Q: How often should I check my tire’s DOT date?
A: Every year. Tires older than 6 years may need replacement even if they look good.

(613) 366-TIRE (8473)

Notice to Our Valued Customers

Please note that our 5100 Bank Street location will be CLOSED from August 2 – August 17 for a short summer break.
We will reopen on Monday, August 18.

Our Embrun location will remain OPEN during this time to serve you.

Thank you for your understanding and continued support!
Have a safe and enjoyable summer!