• Reading a Sidewall
  • Load and inflation tables
  • Tire Pressure Monitoring Systems

    • About the Sidewall

      The sidewall of a tire includes a variety of important information. The numbers and letters identify dimensions and performance standards that allow you to compare tires more accurately and efficiently. This diagram will help you to understand those numbers and letters. For assistance in selecting a replacement tire, always consult your Toyo Tires dealer.

      Load Index

      The load index number and speed symbol correspond to the maximum load-carrying capacity of the tire and its maximum speed capability.

      The load index is an assigned number that corresponds with the load-carrying capacity of the tire. For example, "96" indicates a load-carrying capacity of 1565 lb. at maximum inflation pressure. The load index for most passenger car tires ranges from 75-100. Click here to view the complete load inflation index.

      Load Index Chart

      Speed Symbol Chart

      Speed ratings are determined by indoor laboratory testing methods, which measure high-speed tire durability under controlled test conditions. These test procedures do not take into account underinflation, tire damage, vehicle characteristics or road conditions which can lead to sudden tire failure or loss of vehicle control at much lower speeds than indicated by the tire's speed rating.

      When replacing tires on your vehicle, you should use replacement tires with a speed rating equal to or greater than that of the original equipment tires if the speed capability and handling characteristics of the vehicle are to be maintained. Remember to never operate your vehicle in an unsafe or unlawful manner. Your Toyo Tires dealer can provide you with more information on speed ratings.

      DIAMETER

      The diameter indicates the size of the wheel from one side to the other. You can learn more about changing the diameter of the wheels of your car in the Plus Sizing section.

      RADIAL

      The "R" stands for "radial," indicating the tire has radial construction.

      ASPECT RATIO

      The aspect ratio is the dimensional relationship of the section height to the section width. The lower the aspect ratio, the shorter the sidewall and the wider the shoulder-to-shoulder width.

      WIDTH

      The width of a tire is referred to as its section width. This is the width of an inflated tire in millimeters at its widest point from sidewall to sidewall.

      The section height of the tire is measured in millimeters also. The section height is approximately the distance from the rim to the tread surface of the tire when it is not carrying any weight.

      TIRE TYPE

      Tires with a “P” are for passenger car use. Some passenger car tires may not have a “P” and are considered hard-metric tires. Some light trucks and SUV’s are equipped with original equipment P-metric or hard-metric tires. Tires with a “LT” are for light truck or SUV use only. The "LT" designation stands for "Light Truck." These tires are intended for more severe use often seen on trucks and follow load and inflation standards established by the Tire and Rim Association (TRA). Load Index values and load capacities for these tires can be found in TRA manuals.

      Other Designations

      Mud and Snow. The "M+S" indicates the tire is designed for mud and snow applications. The Mud and Snow designation may also appear as "M/S."

      Mountain Snowflake. The mountain/snowflake designate a tire designed for severe snow conditions.

      TREADWEAR, TRACTION, AND TEMPERATURE GRADES

      Uniform Tire Quality Grading:

      The Uniform Tire Quality Grading System, or UTQG, is a system developed by the government designed to provide consumers with information on tire treadwear, traction, and operating temperature resistance. A number, followed by two to three letters, identifies the grade on the sidewall.

      Treadwear Rating:

      The treadwear grade is a comparative numerical rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 200 would wear twice as well on the course as a tire graded 100. The rating increases in 20-point increments. It is important to note that the true performance of a tire depends upon the actual conditions of its use. Actual conditions may depart significantly from the test conditions due to variations in driving habits, service practices and differences in road characteristics and climates.

      Traction Rating:

      The traction rating indicates the tire's ability to stop a vehicle moving straight forward on wet pavement. The ratings are AA, A, B, and C, with AA being the best.

      Temperature Rating:

      The UTQG Temperature Rating indicates the tire's ability to effectively dissipate heat. The ratings range from A to C, with A being the best.

      U.S. DOT TIRE STANDARD SAFETY CODE

      The DOT tire identification number indicates compliance with all safety standards established by the U.S. Department of Transportation and provides additional information about the tire manufacturer.

      Located on the sidewall of a tire, the complete DOT tire identification number is a combination of up to 12 numbers and letters that provide valuable information.

      • The first two numbers or letters are the plant code where the tire was manufactured.
      • The last three to four numbers represent the week and year the tire was built. The last four digits in this example, 1309, mean this tire was manufactured in the 13th week of 2009.

      Recently it became mandatory to apply a partial DOT serial number on the sidewall opposite the complete DOT serial number. The partial DOT serial shows manufacturer, plant and tire size information. It does not show the week and year that the tire was manufactured, but may still assist consumers in identifying tires should a recall be necessary. The purpose in applying the partial DOT serial number was to facilitate tire identification when the full DOT serial number may have been mounted towards the inboard side of the vehicle, and consequently not visible unless the vehicle was put on a lift for inspection.

      This is the partial DOT number for the full DOT number show above.

      Tires built in the 1990's will have three numbers and may have a triangle to note the decade. The last three digits, 517, plus the triangle in the example above mean this tire was manufactured in the 51st week of 1997. In the absence of the decade triangle, this tire would have been made during the 51st week of 1987.

      For assistance in reading your DOT tire identification number, please contact us.

    • These Load and Inflation Tables are intended to provide assistance when replacing tires with optional tire sizes including “plus sizes” that may not be listed on the vehicle’s tire information placard (T.I.P) or in the owner’s manual. For inflation pressure recommendations for the original equipment (OE) size, refer to the tire information placard (T.I.P.) or owner’s manual. The T.I.P. is commonly found on the vehicle door jam, glove compartment or near the gas cap.

      IMPORTANT: Refer to the vehicle’s owner’s manual for any specific safety advice regarding the application of replacement tires.

      For a complete list of published load and inflation tables, refer to the following organizations:

      • The Tire and Rim Association, Inc.
      • The European Tyre and Rim Technical organization

    • TPMS low tire pressure indicator

      The TPMS low tire pressure indicator is a yellow symbol that illuminates on the dashboard instrument panel in the shape of a tire cross-section with an exclamation point.

      EXAMPLE OF A TPMS WARNING LIGHT

      Common questions about TPMS include:

      • Why is tire pressure important?
      • What is TPMS?
      • Does my vehicle have TPMS?
      • What does the TPMS light on the dash mean?
      • What am I supposed to do when the TPMS light is on?
      • The TPMS light was on, but it went off on its own, do I need to do anything?
      • How much will TPMS repairs cost?

      Why is tire pressure important?

      Air pressure enables a tire to support the load, so proper inflation is critical. Tires can lose one psi (pound per square inch) per month under normal conditions. Additionally, tires can lose one psi for every 10°F temperature drop. Underinflated tires and overloaded vehicles are the leading cause of tire failure. Furthermore, underinflated tires are subjected to heat and stresses that can lead to tire damage and/or unexpected rapid loss of pressure.

      What is TPMS?

      A tire-pressure monitoring system (TPMS) is an electronic system designed to monitor the air pressure inside of a tire and then report real-time tire pressure information to the driver. Even though a TPMS can deliver accurate alerts when properly maintained, it’s not a replacement for manual air pressure checks. Toyo Tires recommends checking tire pressure, including the spare, at least once a month and before every long road trip.

      Does my vehicle have TPMS?

      TPMS is required equipment on model year 2008 and newer passenger cars, light trucks and vans with a gross vehicle weight rating (GVWR) of 10,000 pounds or less. Some vehicles manufactured prior to 2008 are also equipped with TPMS so check your owner’s manual if you are unsure whether your vehicle has this feature.

      Prior to working on your vehicle, your tire dealer should check if it is equipped with TPMS. If your vehicle is equipped with a direct system with wheel mounted sensors, your tire dealer may inform you that additional expense may be incurred if a sensor needs to be replaced and/or reprogrammed prior to beginning work on the vehicle. You should also be aware whether your vehicle is equipped with TPMS so you understand the repairs that may be required.

      What does the TPMS light on the dash mean?

      The yellow TPMS warning light alerts the driver that one or more tires is significantly underinflated and possibly creating an unsafe condition.

      What am I supposed to do when the TPMS light is on?

      Slow down and pull over as soon as it is safe to do so and check and adjust, if necessary, the air pressure in your tires. The warning light may turn off after the inflation pressures are adjusted. However you may need to drive the vehicle for a short period of time so the system can update itself before the light turns off. If your warning light is still on after adjusting the tire inflation pressure according to your vehicle’s tire placard, there may be a malfunction with the TPMS. Bring your vehicle to a professional to diagnose the system.

      The TPMS light was on, but it went off on its own, do I need to do anything?

      Yes. The light came on because the TPMS identified either a system malfunction or one or more tires with pressure below the threshold. Any time the light illuminates, you should check the air pressure of your tires with a gauge.

      How much will TPMS repairs cost?

      Maintaining your TPMS may come as an unexpected expense when taking your vehicle in for service or tire replacement. Just like any part on your vehicle, the TPMS sensor can corrode or wear out over time. Your tire dealer should diagnose any problems before working on your vehicle so you understand the service required and associated costs. Tire dealers cannot bypass the TPMS system. They must repair, replace or recalibrate failed sensors and ensure the TPMS system is operational to be in compliance with the law.