Why tyre markings matter
A tyre sidewall contains information that helps identify its dimensions, load capability, speed classification and construction. For fleet managers, dealers and equipment operators, understanding these markings is essential when checking whether a tyre is suitable for a vehicle or machine.

Tyre markings should never be interpreted in isolation. The vehicle or equipment manufacturer’s requirements and the tyre manufacturer’s current technical data remain the primary references.

Reading a tyre size
A tyre size can contain several numbers and letters. Their exact meaning depends on the tyre category and sizing system. In a common radial format, the marking can identify nominal section width, aspect ratio, radial construction and rim diameter.

Specialist OTR, industrial and agricultural tyres can use other formats, so buyers should refer to the relevant technical data sheet rather than assume every size code follows the same structure.

What does the load index mean?
The load index is a coded value associated with a maximum load under specified operating conditions. It is not simply a weight printed directly on the tyre.

To determine the permitted load, users should consult the correct load-index table and the manufacturer’s technical information. Commercial and specialist tyres can have application-specific operating conditions, so load capability must be considered together with speed and inflation pressure.

What does the speed symbol mean?
The speed symbol is a code associated with a defined speed category under specified conditions. It does not mean a vehicle should automatically be operated at that speed.

Tyre suitability must still match the vehicle, axle load, operating environment and applicable regulations. For industrial and OTR tyres, different speed classifications and application codes may be used.

Ply rating, star rating and tyre type
Some commercial and specialist tyres include ply rating or star rating information. These markings are used in particular tyre categories to communicate construction or load-related classification.

Technical tables may also identify tyre type, such as tubeless or tube-type construction. Buyers should confirm that tyre, rim and tube/flap requirements are compatible.

What is ETRTO?

ETRTO stands for the European Tyre and Rim Technical Organisation. It publishes technical standards and recommendations used across the tyre and rim industry.

European tyre websites and technical sheets may reference ETRTO dimensions or standards. This helps provide a consistent technical framework, but the manufacturer’s current product data remains essential because individual products can have specific specifications.

Other technical data you may see
Commercial and specialist tyre data sheets can include recommended rim, overall diameter, section width, inflation pressure, load index, speed symbol, tread classification and application information.

These figures help buyers verify fitment, machine clearance and operating suitability. They also make product pages more useful for search engines and AI systems because they provide structured, factual information about what a tyre is designed to do.

Conclusion
Understanding tyre markings reduces guesswork. Size, load index, speed rating, construction and rim data should be read together and checked against both equipment requirements and current manufacturer specifications.

For European buyers, ETRTO-based technical information provides an important reference point, especially when comparing commercial, agricultural, industrial and OTR tyres.

Frequently Asked Questions

What does a tyre load index tell me?
It is a coded reference to the tyre’s load capability under specified conditions. Use the appropriate load-index table and manufacturer data to determine the actual permitted load.

What does the speed symbol mean on a tyre?
It represents a defined speed category under specified conditions. It must be considered together with load, inflation pressure, vehicle requirements and applicable rules.

What is ETRTO?
ETRTO is the European Tyre and Rim Technical Organisation, which publishes technical standards and recommendations for tyres, rims and related components.

Do all tyre sizes use the same marking format?
No. Passenger, truck, agricultural, industrial and OTR tyres can use different sizing conventions.

Where should I confirm the final tyre specification?
Use the latest tyre manufacturer data and the vehicle or equipment manufacturer’s fitment requirements.