Commercial truck tire sidewall markings are not just small technical text molded into rubber. They tell you the tire size, load information, construction type, DOT identification, inflation relationship, and whether the tire is designed for specific service conditions. If you buy tires for a fleet, shop, or distribution program, reading those markings correctly helps prevent poor fitment, overload risk, uneven wear, and costly replacement mistakes.
Why Sidewall Markings Matter Before You Buy
A commercial tire can look like the right fit at a glance and still be wrong for the vehicle, axle position, load, rim, or route. That is why sidewall markings matter. They give you the starting data for a smarter buying decision before you compare tread pattern, warranty, or price.
In 2026, the topic became even more relevant because FMCSA clarified through its Tire Load Markings final rule that Federal Motor Carrier Safety Regulations do not require tire load restriction markings on CMV tire sidewalls. That clarification helps reduce confusion, but it does not make sidewall information irrelevant. It simply makes it more important to understand what the markings do tell you, and what they do not.
The sidewall gives you the starting data. The right tire decision still depends on load, axle position, rim fitment, route, and manufacturer guidance.
What Information Is Usually Found on a Commercial Truck Tire Sidewall
For heavy vehicle tires, federal safety standards require a set of markings that help identify the tire and its intended capacity. These markings can include the DOT symbol, Tire Identification Number, tire size designation, maximum load ratings, corresponding cold inflation pressure, construction type, tubeless or tube-type designation, regroovable marking when applicable, and load range letter.
Not every marking should be used the same way. Some identify the tire. Some describe construction. Some indicate load and pressure relationships. Others help with age tracking and recall traceability. A good buyer reads the full sidewall, then checks the product specification table and the vehicle requirements.
| Sidewall Marking | What It Tells You | Why It Matters |
|---|---|---|
| Tire Size | Physical size format, such as 11R22.5 or 295/75R22.5 | Helps confirm fitment, rim compatibility, and replacement match |
| DOT / TIN | Department of Transportation identification and traceability code | Used for identification, recall tracking, and tire age review |
| Load Index | Numerical load capacity code | Helps compare load capacity across tire sizes and applications |
| Load Range | Letter-based strength/load category | Useful for comparing construction category, but not a complete buying decision by itself |
| PR / Ply Rating | Historical strength reference | Often misunderstood as literal ply count in modern radial tires |
| Max Load Single | Maximum load when the tire is used alone on one side of an axle | Important for single fitment positions |
| Max Load Dual | Maximum load per tire when used as a dual pair | Critical for dual assemblies because per-tire ratings differ from single use |
| PSI Cold | Cold pressure tied to a load rating | Not automatically the universal operating pressure for every truck |
| Radial | Radial construction | Confirms construction type for modern commercial tire applications |
| Tubeless | Tire is designed for tubeless use | Helps confirm mounting and rim expectations |
| Regroovable | Tire is designed for regrooving when marked as such | Relevant for maintenance planning, only when proper procedures and rules are followed |
How to Read Truck Tire Size Like 11R22.5 or 295/75R22.5
Commercial tire sizes appear in different formats. Two common examples are 11R22.5 and 295/75R22.5. Both can be found across commercial truck tire lineups, including KADO models such as KDD-7, KDT-1, and KDA-5.
11 refers to approximate section width in inches. R means radial construction. 22.5 refers to rim diameter in inches.
295 is the section width in millimeters. 75 is the aspect ratio. R means radial construction. 22.5 is the rim diameter in inches.
Size is a starting filter, not the whole decision. Before choosing, compare the tire’s load index, pressure/load relationship, rim specification, and application. KADO’s commercial tire lineup makes this easier by separating drive, trailer, and all-position options.
Load Index Load Range and PR What Is the Difference
Load terminology causes a lot of buying mistakes. The terms sound similar, but they are not interchangeable.
This is why buyers should not choose a tire by “ply rating” alone. A tire’s actual max load, load index, load range, rim, and pressure relationship need to be compared together. On KADO product pages, these details appear in the technical parameters table, including PR, Load Index, Max Load Single/Dual, Pressure, Rim, section width, and tread depth.
For example, the KDT-1 trailer tire and the KDD-7 drive tire both list size options and technical parameters that help buyers compare real specifications instead of relying on one sidewall term.
Single vs Dual Load Ratings Explained
One of the most important markings on a commercial tire is the difference between single and dual load. A tire used alone on one side of an axle does not operate the same way as a tire paired side by side in a dual assembly.
In dual use, heat, spacing, load sharing, and real-world service conditions are different. That is why dual load ratings are usually lower per tire than single ratings. Do not take the single load rating, multiply it, and assume the dual setup is automatically correct.
| Marking | What It Means | Common Mistake |
|---|---|---|
| Max Load Single | Maximum load when the tire is used alone on one side of an axle | Using this number for a dual assembly without checking the dual rating |
| Max Load Dual | Maximum load per tire when used in a dual pair | Assuming dual tires can each carry the same load as single tires |
| PSI Cold | Cold inflation pressure connected to the load rating shown | Treating it as the universal recommended pressure for every application |
| Load Index | Numerical indicator of load capacity | Ignoring it and buying by size only |
| Load Range | Letter category tied to tire strength/load class | Using it alone instead of comparing actual capacity and application |
| Tire Size | Dimensional fitment information | Assuming same size always means same load, tread, and duty suitability |
What PSI Cold Really Means
The pressure shown on a sidewall is tied to a load rating. It is not automatically the recommended operating pressure for every vehicle, every load, or every route. Actual operating pressure should be determined with the tire manufacturer’s guidance, vehicle requirements, axle load, and service conditions in mind.
The word “cold” matters because tire pressure changes after the tire heats up from driving. Checking pressure cold gives a cleaner baseline. In fleet operations, pressure discipline affects heat, wear, rolling resistance, casing life, and fuel cost.
For a deeper operational view, KADO’s article on tire pressure and fuel efficiency explains why inflation habits matter beyond basic compliance.
DOT TIN and Tire Age How to Decode the Date
The DOT Tire Identification Number, often called the TIN, helps identify the tire. It is also the code buyers and maintenance teams use to check the tire’s manufacture date. For tires made after 2000, the last four digits show the week and year of manufacture.
For example, 0324 means the tire was manufactured in the third week of 2024. NHTSA also notes that the TIN may not appear on both sidewalls, so if you do not see the full code on one side, check the other side.
Tire age alone does not tell the whole safety story. Storage, heat, service conditions, load history, visible damage, and manufacturer recommendations still matter. But age is a key data point, especially when buying inventory, evaluating spares, or comparing older stock.
Why Sidewall Data Is Not Enough by Itself
Sidewall markings are essential, but they are not the entire decision. For heavy vehicles, tire and rim selection has to support the axle system and the vehicle’s load requirements. A tire that appears to match by size can still be a poor choice if load capacity, rim compatibility, duty cycle, or position requirements are wrong.
This is why a good buyer does not stop at “same size.” The real question is whether the tire matches the full operating context.
Common Buying Mistakes Fleets Make
Many tire problems begin before the tire is installed. They start with a buying decision that looked reasonable on paper but ignored one important specification. Here are the most common mistakes to avoid.
| Common Mistake | Why It Is Risky | Better Approach |
|---|---|---|
| Choosing only by size | Same size does not guarantee the same load rating, application, tread, or rim fitment | Compare size, load index, load range, pressure, rim, and position |
| Ignoring dual load rating | Dual operation has different load conditions than single operation | Use the dual rating when evaluating dual assemblies |
| Treating sidewall PSI as universal pressure | Can lead to poor heat, wear, and load management | Match pressure to actual load and manufacturer guidance |
| Ignoring tire age | Older tires may require closer review even if tread looks acceptable | Decode the DOT/TIN and inspect condition carefully |
| Mixing applications without reason | Drive, trailer, and all-position tires are designed around different priorities | Match tire type to axle position and route demands |
| Skipping rim compatibility | Incorrect fitment can create safety and performance problems | Confirm rim width and diameter before ordering |
How KADO Product Pages Help You Compare the Right Specs
KADO product pages are useful because they give buyers the technical details needed to compare tires beyond the product name. You can review tire size, PR, load index, overall diameter, section width, tread depth, rim, max load single/dual, pressure, and tire position.
If you are comparing trailer applications, the KDT-1 trailer tire is a natural place to start. For traction-focused drive positions, compare a model like KDD-7. For all-position or steer-oriented planning, review the technical table on KDA-5.
FAQ
What do commercial truck tire sidewall markings mean?
They identify key tire information such as size, DOT/TIN, load capacity, load range, inflation pressure relationship, construction type, and sometimes regroovable or speed-related information.
How do you read a truck tire size like 11R22.5?
In 11R22.5, “11” refers to approximate section width in inches, “R” means radial construction, and “22.5” is the rim diameter in inches.
What is the difference between load index and load range?
Load index is a numerical code for load capacity. Load range is a letter-based category related to tire strength/load class. Both should be read with actual max load, pressure, rim, and application.
What does Max Load Single and Max Load Dual mean?
Max Load Single applies when the tire is used alone on one side of an axle. Max Load Dual applies per tire when the tire is used in a dual pair. The numbers are not the same because the operating conditions are different.
Does the PSI on the sidewall mean recommended tire pressure?
Not always. The sidewall PSI is tied to a load rating. Actual operating pressure should be determined using load, axle position, tire manufacturer guidance, vehicle requirements, and service conditions.
How do I find the age of a commercial truck tire?
Look for the DOT/TIN. For tires made after 2000, the last four digits show the week and year of manufacture. For example, 0324 means the third week of 2024.
What does DOT TIN mean on a tire?
DOT indicates certification to applicable federal motor vehicle safety standards. TIN stands for Tire Identification Number and helps identify the tire for traceability, age review, and recall-related purposes.
Can I choose a truck tire by size alone?
No. Size is only one factor. You should also compare load index, load range, single/dual ratings, pressure, rim compatibility, axle position, route demands, and manufacturer guidance.
Sidewall markings help you compare commercial truck tires intelligently. They show the tire size, DOT/TIN, load information, cold pressure relationship, construction type, and other details that matter before a purchase. But they are not a complete decision by themselves.
The right tire choice still depends on the full operating picture: axle load, tire position, rim compatibility, pressure discipline, route conditions, duty cycle, and manufacturer guidance. When buyers read the sidewall correctly and compare it with the technical specs, they make better decisions for uptime, safety, and long-term tire cost.
References
- U.S. Department of Transportation / FMCSA. Parts and Accessories Necessary for Safe Operation; Tire Load Markings. Final rule, 2026.
https://www.transportation.gov/regulations/federal-register-documents/2026-03260 - 49 CFR 571.119. Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 10,000 pounds.
https://www.law.cornell.edu/cfr/text/49/571.119 - 49 CFR 571.120. Tire selection and rims for motor vehicles other than passenger cars.
https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.120 - NHTSA TireWise. Tire safety ratings and awareness, including DOT/TIN and tire age guidance.
https://www.nhtsa.gov/vehicle-safety/tires
