Choosing the Right Tire Size for Your Vehicle

Department of Transportation (DOT) Safety Code

The DOT marking confirms that a tire complies with applicable U.S. safety standards. Following the DOT symbol is the Tire Identification Number (TIN), which provides manufacturing information.

The initial characters identify the manufacturer and production facility. The final four digits indicate the week and year the tire was manufactured.

This information helps identify when a tire was produced, although tread wear and overall condition remain the primary factors when determining replacement timing.

UTQG Code

The Uniform Tire Quality Grading (UTQG) system is administered by the National Highway Traffic Safety Administration (NHTSA). It evaluates tires based on government-mandated testing across three categories:

• Treadwear – Indicates the relative wear rate of a tire within a manufacturer’s product lineup

• Traction – Grades (AA, A, B, C) that reflect a tire’s ability to stop on wet pavement

• Temperature – Grades (A, B, C) indicating resistance to heat buildup

Icons and Symbols

Some tires feature icons or letter markings that indicate specific performance characteristics or intended use.

M+S (Mud and Snow) markings identify tires designed for use in mud and snow conditions and are commonly found on all-season tires

Additional symbols may appear depending on the tire type and application

Your vehicle manufacturer specifies the recommended tire size and specifications for your vehicle. This information can typically be found in the vehicle owner’s manual, often stored in the glove compartment, or on the tire information placard located on the driver’s side door or door jamb.

These sources also list the recommended inflation pressure for your vehicle. For details on reading tire sidewall markings, refer to the section above on locating tire size information on your tire.

OE stands for Original Equipment, meaning the tires were approved by the vehicle manufacturer for installation when the vehicle was produced.

Some automakers, including Audi, BMW, Mercedes-Benz, and others, equip their vehicles with tires developed specifically for their models. These tires feature manufacturer-specific OE markings on the sidewall.

When replacing OE tires, Michelin recommends installing tires with the same approved OE marking whenever possible. This helps maintain the vehicle’s intended handling, comfort, and performance characteristics, while also ensuring proper load and speed ratings.

★ – BMW, MINI

MO – Mercedes-Benz

MO1 – Mercedes-AMG

AO – Audi

RO1 – Audi quattro

VO – Volkswagen

N0, N1, N2, N3, N4 – Porsche

These markings indicate that the tire was developed and approved for a specific manufacturer or vehicle model.