Tire code

A tire code is a standardized alphanumeric code found on the sidewall of automobile tires. It explains the characteristics of the tire.

Example

• Size: 235/50ZR18
• 225 mm wide
• 65 aspect ratio (sidewall height divided by tire width, in percent)
• R = radial tire, ZR = radial tire with Z or higher speed rating
• 17 inch wheel

Goodyear Eagle RS-A (High Performance All-Season)

• Size: 235/50ZR18
• Sidewall Style: Blackwall
• Serv. Desc: 97W Load Index 97 = 1609lbs (730kg) per tire
• Speed Rating “W” = 168mph (270kph)
• UTQG: Treadwear: 260
• Temperature: A260 A A

Speed ratings are not in alphabetical order. Example: H is higher than T.

External link

• Tire Basics: What Drivers Should Know About Tires