Tire sidewall markings decoder

What can tire sidewall markings tell you?

A sidewall identifies the tire size, construction and service description; other marks may describe manufacture date, snow classification, load variant or product design. These are reference facts, not proof that a tire is approved for your vehicle. Check the exact tire, vehicle placard and maker instructions.

Decode size, load and speed together

Enter the printed size and ratings, for example 225/45 R17 94W XL. DOT dates are separate.

Tire size

Section width: 225 mm
Aspect ratio: 45%
Sidewall height: 101.3 mm
Overall diameter: 634.3 mm
Construction code: R
Rim diameter (in): 17

225/45R1794WXL

Single fitment: kg per tire · 94: 670
Speed symbol · W: 270 km/h

Extra load / reinforced. XL identifies a load variant. It does not specify the vehicle’s pressure or approve a replacement.

Load and speed are reference table values, not vehicle approval. For dual use, verify the complete product specification.

Compare this size Read a separate DOT date

Reference-table value only. Always match your vehicle placard and tire sidewall markings.

Read the common markings

These examples explain common marks. Application, pressure, legal requirements and safe use depend on the exact tire and vehicle.

Marking, What it tells you and what to verify
Marking	What it tells you and what to verify
205/55 R16 91V	205 mm nominal section width, 55% aspect ratio, radial construction, 16 in rim, load index 91 and speed symbol V. Table values do not approve a replacement for a vehicle. NHTSA
DOT / TIN	For a post-2000 U.S. DOT tire identification number, the final four digits give manufacture week and year. The full date code may appear on only one sidewall; age alone sets no universal replacement deadline. NHTSA
M+S	A mud-and-snow marking. It is not by itself proof of severe-snow testing or compliance with every local winter rule. UN R117
3PMSF	The Alpine three-peak mountain/snowflake symbol identifies a tire classified for severe snow under UN Regulation No. 117. Check the current rule for your vehicle and place of use. UN R117
XL / Reinforced	A reinforced or extra-load tire variant. Use the complete load index, approved tire data and vehicle instructions; the letters alone do not set a universal inflation pressure. UN R117
MAX LOAD / MAX PRESS	Limits printed for the tire, not the vehicle’s recommended load or cold inflation pressure. Use the vehicle placard and owner manual for normal operation. NHTSA
UTQG	U.S. treadwear, wet-traction and temperature grades where the rule applies. The treadwear number does not predict real-world mileage or certify suitability for a vehicle. 49 CFR 575.104
RUN FLAT / RFT	Run-flat codes depend on the exact product. Follow the tire and vehicle makers for drive-on limits and repairability. Bridgestone
OUTSIDE / →	OUTSIDE and direction arrows identify mounting orientation for certain tread designs. Follow the markings and the product fitting instructions. Michelin

What the markings cannot approve

A matching size or higher table rating does not establish rim approval, vehicle clearance, correct pressure, legal winter use or safe condition. Check the exact product data, vehicle placard, local rules and physical tire condition before use.

Service description

Load and speed are reference table values, not vehicle approval. For dual use, verify the complete product specification.

Source: Michelin — How to read a tyre size; construction/wheel diameter; XL and Reinforced; maximum load/speed; tyre pressure · DVSA — Load rating; single and dual index explanation (vehicle/axle values are distinct from per-tire reference values)

XL identifies a load variant. It does not specify the vehicle’s pressure or approve a replacement.

These marks are retained for product-specific review. No meaning or numeric rating is assumed.

OEM tire markings: source-checked reference

An Original Equipment (OE) mark identifies a tire version developed and approved for a vehicle maker, often for a particular model or application. It is more specific than the tire model name alone.

Sidewall marking, Vehicle maker, What the mark supports, What it does not prove
Sidewall marking	Vehicle maker	What the mark supports	What it does not prove
★ (star)	BMW / MINI	A BMW-tested, vehicle-tuned tire version.	Approval for every BMW model or wheel size.
AO / AO1 / RO1 / RO2	Audi	An Audi Genuine tire version tested against model-specific criteria.	Rolls-Royce approval; RO1 and RO2 are Audi markings.
MO / MOE / MO1 family	Mercedes-Benz / Mercedes-AMG	A Mercedes OE version; MOE identifies an extended-mobility variant.	Interchangeability between every MO-family version.
N / N0 / N1 and newer N-series codes	Porsche	A tire version tested and approved by Porsche for specified applications.	That every N-marked version suits every Porsche model or axle.
VOL	Volvo	A Volvo-tested and customized tire version for a specified model.	That size, load index, speed rating and axle position can be ignored.

Match the exact vehicle, model, axle and tire specification in the owner manual or manufacturer-approved tire list. An OE mark does not replace the required size, load index, speed rating, wheel compatibility, pressure or physical-clearance checks.

Sources for the basic markings

These sources support only the marking explanations above. The OEM table has its own manufacturer sources. No source here approves a specific tire for a specific vehicle.

Sources checked: 2026-09-23

OEM marking sources reviewed

The mappings above are limited to markings confirmed by vehicle-maker material or a current tire-manufacturer OE reference. Manufacturer guidance remains authoritative for the exact vehicle and tire version.

Checked: 2026-09-04

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Last reviewed: 2026-09-23