Tyre Sidewall Markings Decoded: What Your Tyre Size Really Means

Wondering what the markings, numbers, codes, and symbols on a tyre’s sidewall stand for? We suggest you go through this comprehensive article to grab the real meaning behind the intriguing codes on tyre sidewalls.

Whether you operate a vehicle with industrial, agricultural needs, and off-road capabilities, it’s critical to know what the different markings on the sidewall of the tyre stand for.

Understanding tyre sizes is essential for vehicle owners, drivers, and most importantly, large fleet and construction vehicle owners.

The mix of markings, codes, and numbers on the tyre sidewalls holds significance for stakeholders managing a fleet and logistics operators, ensuring safety, cost-effectiveness, and legal compliance.

What Are Tyre Sidewall Markings?

Tyre sidewall markings provide valuable instructions from manufacturers to users. The information revealed here provides essential data on the size, maximum load capacity, construction, and maximum speed limit that the tyre can sustain.

Additionally, the marking on the tyre sidewall also helps users keep track of the tyre’s performance characteristics and reminds them of the manufacturing date. Understanding tyre sizes.

For example, if the tyre on your truck has this writing BIRLA 10.00-20 16P.R. BIAS PLY 146/142J, then here’s the easiest way of understanding tyre sizes:

Tyre Sidewall Marking Difference: Radial Tyre vs Bias Ply Construction

Standard tyre sidewall markings have the letter "R" for Radial construction or a "-". On the other hand, bias tyre sidewall markings explicitly show "BIAS", or "BIAS PLY", on the tyre's body.

It may also use the letter "B" or "D" in contrast with the "R" used for Radial construction to denote bias construction. For example, you can expect a sidewall marking like this on Birla Tyres: “BIRLA 10.00-20 16PR BIAS PLY 160/157K”

Breaking Down the Tyre Code

Understanding tyre sizes is critical as it helps develop the right habits for using and maintaining the tyres for your vehicle. We have broken down each component of what the writing on the sidewall of a tyre stands for.

10 inches (Section Width)

This number is used to denote the width of the tyre measured in millimeters. The measurement follows one side of the tyre’s wall to the other.

“-” (Diagonal Construction)

This letter suggests that the tyre has a bias ply construction. Under such constructions, internal layers get arranged in a straight line from bead to bead.

20 (Wheel Rim Diameter)

The diameter of the wheel rim of a tyre is designed to fit into what you call the wheel diameter. The number 20 here stands for wheel diameter. The unit for measuring the wheel diameter is 20 inches.

While 20-inch rims are frequently available in the market, you see trucks using larger wheel rims as well. If you want to know the right size of your truck tyre, look at the sidewall of it.

Other Key Sidewall Markings

Aside from the key ratings and markings on the sidewall of the tyre, users may also discover a different range of markings. Load index, speed rating, and tread wear indicator are among the key markings to look at when analyzing the efficiency and longevity of the tyre.

146/142 (Load Index) & J (Speed Rating)

The load index makes up for the additional numerical codes and the maximum weight a single tyre can safely carry when properly inflated. This is a letter to indicate the maximum speed limit a tyre can handle and how fast it can help the vehicle run.

The marking may vary depending on the speed limit that the tyre can match. If one such match detects ‘J’, then the tyre can achieve a speed limit of 100 km/h while bearing the load index of 146/142.

Manufacturing Date (DOT Code)

The manufacturing date on the tyre is visible in the last four digits of the DOT (Department of Transportation) code. The first two digits of the manufacturing date on tyre sidewalls represent the week of the year (01-53) when the tyre was manufactured.

The last two digits of the number suggest the years when the tyre was manufactured. Therefore, if the manufacturing date on the tyre reads 3423, it means that the tyre was manufactured in the 34th week of 2023.

Tread Wear Indicators

While this is more of a safety mark for your vehicle tyre than a marker to understand tyre sizes, tread wear indicators are also an important part of the tyre information you can access on the tyre wall.

These indicators are signs spaced evenly along the tread of the tyre. It enables users to identify how much of the tread depth your tyre has already used up.

Tyre Type:Tube-type (TT) or Tubeless (TL)

Among the additional markings, the tyre type (e.g., tube-type or tubeless) is also a critical marking to take note of.

Aside from the indicators of size, speed, aspect ratio, and safety, the tyre sidewall can also bear information regarding the brand and model.

Understanding Tyre Sizes: Why Does it Matter to Logistics Operators & Fleet Managers?

With the understanding of the right tyre sizes and quality, fleet managers and vehicle owners make the right tyre purchase decision. The right decision on vehicle tyres leads to better vehicle performance, improved fuel efficiency, safety in handling, Legal compliance, and ease of mind for the operators and logistics owners.

Vehicle fleet owners and logistics managers can enjoy the following benefits once they opt for the right vehicle tyre after a thorough understanding:

1. Improved Vehicle performance

Optimal handling: Once vehicle owners choose the right truck and bus tyre, they are choosing optimal performance and easy handling of their vehicles.

The aspect ratio, construction type, and tread patterns of the tyres determine how efficiently the vehicle owners can drive and handle it at different road conditions.

Consistent traction: Whether you’re a fleet manager or a logistics operator, it’s critical to know and understand what markings such as M+S or 3PMSF stand for.

An M+S marking means that the road can handle mud and snow conditions. With a 3PMSF or three-peak mountain snowflake marking, a tyre can handle severe winter conditions.

Consistent performance: With mixed tyre designs and tread patterns, tyres can retain consistent performance on different and changing road conditions.

2. Fuel Efficiency

Fuel efficiency is critical to large truck fleets, industrial, and construction vehicles. Tyre markings related to rolling resistance (the energy tyres spend when they roll) and correct air pressure help users understand the energy the vehicle will take to navigate a certain distance. Proper air pressure and tyre inflation ensure lower rolling resistance, contributing to fuel efficiency.

3. Safety and Handling

Understanding tyre sizes and different markings on the tyre’s sidewall provides drivers with instructions on how to handle the vehicle. They can make more informed decisions regarding the level of inflation that’s capable of handling a specific weight and a speed limit.

Additionally, the Tread wear indicators (TWI) on the tyre work as a significant safety marker notifying the vehicle owners when to change the tyre.

4. Legal Compliance

Understanding tyre sizes, speed rating, and other information engraved on the tyre sidewall helps owners stay compliant with the legal aspect of vehicle ownership.

Some regions require vehicle tyres to pass specific tests and standard marks before they are ready for large-scale usage. The Bureau of Indian Standards (BIS) mark is a marker to look out for legal compliance.

Additionally, vehicles operating with worn-out tyres that pass the legal tread limit can be detained by the legal authority. Such detention can create serious operational hurdles for logistics and fleet owners.

Choosing the Right Tyre with Birla Tyres!

Birla Tyres designs vehicle tyres for heavy-duty trucks and buses with proper markings, giving the users transparency and ensuring legal compliance.

Whether you need a vehicle for off-roading, mining, or heavy-duty construction work, you can expect tyre size markings, DOT code, load index, and speed rating.

Birla Tyres doesn’t make it difficult for you to choose the right tyre for the right vehicle and road conditions. Additionally, the error-free markings ensure the authenticity of the tyre and make it easy for users to maintain it.

FAQs

How do you know if Tyres are fake?

A: You can analyze if the tyres are fake by checking the marking on the sidewall. Blurred, uneven, or poorly printed characters on tyres suggest duplicity. Misspellings are also suggestive of a tyre being fake. Most fake tyres also contain uneven tread patterns.

What are the Wall Markings on Tyres?

A: The wall markings on the tyres (in millimeters) define the distance between the outer and the inner sidewalls. For example, if you have a 205 mm marking, it means the tyre is 205 mm wide. The tyre also has an aspect ratio (height as a % of width) engraved after the marking of its width.

How to Tell if a Tyre is Brand New?

A: Every new tyre comes with the tread wear indicator. New tyres typically have a tread wear indicator hidden inside the grooves. If the tyre’s TWI shows on the surface, then it means it’s an old tyre.