How we source tire data

Tire numbers matter: a wrong load or pressure figure can damage equipment or hurt someone. So every figure on TireRig comes from a primary source, and every table says which one.

Sources we use

• Manufacturer technical data books — dimensions, load and inflation tables, rolling circumference and revolutions per mile (for example Bridgestone/Firestone, Michelin, Goodyear, Continental, BKT, Titan, Apollo).
• Industry standards — The Tire and Rim Association (TRA, USA) and ETRTO (Europe) for size designations, codes such as R-1/R-1W, E-3/L-3, and load index definitions.
• Regulators — NHTSA (USA) for DOT codes and tire markings.

Rules we follow

• We never copy numbers from blogs, forums or AI answers.
• When manufacturers differ (they often do — two 11R22.5 tires can differ by 20+ revolutions per mile), we show the range and name the models, not one “average” number.
• Load and pressure: we point you to your tire maker's table for your exact tire and load. We do not invent “recommended pressures”.
• Every data page shows the source and the date it was last checked.
• Calculators show their formula, so you can check the math.