How to Read a Tire Sidewall

Your tire’s sidewall is packed with information—size, construction, load capacity, speed rating, manufacturing details, and more. Once you know how to read those letters and numbers, you can choose the right tires with confidence.

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P‑Metric tire codes

A P‑Metric code begins with a letter that indicates tire class, followed by size and construction details.

• Tire class:
• P = P‑Metric passenger tire built to U.S. standards
• LT = Light Truck tire (built to U.S. standards but not part of P‑Metric)
• No letter = Euro‑Metric (also called Hard Metric) passenger tire
• Section width: the 3‑digit width in millimeters (e.g., 205)
• Aspect ratio: the 2‑digit sidewall height as a percentage of section width (e.g., 65 means 65% of 205 mm)
• Construction: R = radial; D = diagonal bias
• Wheel diameter: rim size in inches (e.g., 16 fits a 16‑inch wheel)

Learn more: - Tire dimensions - Tire construction - Euro‑Metric vs. P‑Metric tires - Passenger vs. Light Truck tires

High flotation tire codes

High flotation codes look similar but list measurements differently.

• Overall diameter: tire height in inches (e.g., 35)
• Tire width: inches with a decimal (e.g., 12.50)
• Construction: R = radial; D = diagonal bias
• Wheel diameter: rim size in inches (e.g., 17)
• Load range (for many LT flotation tires): a letter indicating air capacity/carrying ability (commonly C, D, or E)

Learn more about flotation tires.

Other sidewall markings

Load index and speed rating

• Load index (number) = how much weight the tire can carry at specified pressure. Example: 92 corresponds to 1,389 lbs at 36 psi. Check our load index chart for exact values: Load range and load index.
• Speed rating (letter) = maximum sustained speed under controlled test conditions. Example: H = up to 130 mph. Always follow posted speed limits.

Learn about speed ratings.

U.S. DOT and safety standard markings

• DOT indicates the tire meets U.S. Department of Transportation requirements for road use.
• Plant code: the two letters after DOT identify the manufacturer and plant.
• Manufacturer codes: indicate size and brand characteristics (for internal use).
• Date code: four digits at the end; first two = week, last two = year. Example: 1016 = 10th week of 2016.

Treadwear, traction, and temperature (UTQG)

• Treadwear: relative wear vs. a control tire rated 100. Example: 520 suggests over five times the control tire’s wear.
• Traction: wet straight‑line stopping (AA, A, B, C).
• Temperature: heat resistance (A, B, C).

Learn about UTQG.

Maximum load capacity and inflation pressure

• Max load: the most weight the tire can carry at its max pressure.
• Max pressure: do not exceed. Example: 44 psi max, 1,400 lbs capacity.
• Important: These are tire limits, not your vehicle’s settings. Always use your vehicle manufacturer’s recommended cold inflation pressure.

Learn about tire pressure.

Ply construction

Sidewalls list the materials and number of plies used in the tread and sidewall. This helps you understand durability and ride characteristics.

Explore tire construction.

Rotation direction and mounting

• Directional tires: arrows show the required direction of rotation.
• Asymmetrical tires: “Outside” is labeled; that side faces outward.
• Some tires are both directional and asymmetrical; follow both indicators.

Learn about tread patterns.

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Services and store FAQs

• What services do tire centers typically include with purchase?
• Professional mounting and computer balancing
• New rubber valve stems or TPMS service as needed
• Old tire disposal
• Rotation and rebalancing at recommended intervals (often included or discounted)
• Flat repair policies and optional road‑hazard coverage vary by retailer

• Exact inclusions vary by location—confirm at checkout.

• Can I get a free tire inspection at Discount Tire?

• Availability can vary by store. Your local team can advise on complimentary services like air‑pressure checks, tread‑depth measurements, and visual inspections. To confirm, find a store or schedule a visit.

• Where can I find Discount Tire Company, and what services do they offer?

• Use the nationwide store locator to find the location nearest you. Stores can assist with tire selection, installation, rotation, balancing, flat repair, and TPMS services. You can also browse education resources in our Tire Education hub.

• What free tire services does Discount Tire offer?

• Offerings may vary by location. Contact your nearby store to confirm available no‑charge services and current promotions: Find a store or view promotions.

• Looking for alignment information?

• For alignment‑related needs or referrals, please contact your local store. They can confirm availability or recommend next steps: Find a store.

Have questions? We’re here to help—make an appointment or find your store.