What do the sidewall markings on my tire mean?

English: tire identification diagram showing v...

English: tire identification diagram showing various labeling features, English terms. (Photo credit: Wikipedia)

September 25 2012 • toyota.com frequently asked questions

The sidewall markings on a tire provide descriptive information about the tire’s design.

Step by step let’s interpret the sidewall markings on the tire image example below by reading clockwise from P215/65R16, which is located on the lower left-hand corner of the tire illustration:

  • P – Passenger vehicle tire
  • 215 – This number specifies the width in millimeters (i.e. 215 mm)
  • 65 – This number is the Aspect Ratio, the ratio of sidewall height to width
  • R – Radial
  • 16 – This number designates the tire’s diameter in inches (i.e. 16″)
  • 89 – This number indicates the tire’s load-carrying capacity, known as the Load Index; as the number for the load index increases so does the load-carrying capacity (All passenger car tires in the U.S. are also marked with their actual load limit in pounds)
  • H – This letter denotes the Speed Rating, the maximum tire speed under controlled test conditions (H” in this example is one of several types of speed ratings)
  • Treadwear – Wear rate of the tire determined by field testing following a government specified course
  • Traction – How well the tire stops on wet roads in government tests, graded using the letters AA, A, B, or C with AA being the highest in performance
  • Temperature – The tire’s resistance to the heat generated by running at a high speed in government tests, which is also graded using A, B, or C with A being the best
  • psi (pounds per square inch) – The maximum cold inflation rating for the tire
  • DOT (Department of Transportation) – This symbol indicates the tire meets or exceeds United States DOT safety standards; the letters and numbers following the DOT symbol provide information about the tire manufacturer, tire size, and the date it was manufactured

For information on tire size and pressure specific to your vehicle please refer to Tires in the index of your owner’s manual for the appropriate page numbers. Additional tire information is also available in the tire section of the DOT website.





5 car noises you should not ignore

It’s easy to say that you don’t have money to fix some of these small problems now, but wait a little while and these small problems turn into money hungry monsters. You’ll be paying a lot more later on down the road.

1. Increased thwacking sound as your vehicle accelerates.

Your tire is dying. The tread on the tire is departing and pieces of it are whipping the inside of the wheel well.  In some instances, large pieces can become dislodged and mangle the exterior or underside of your vehicle, causing more damage.

2. High-pitch screeching sound under hood

A high-pitched screeching sound that comes from under your hood and matches engine speed is often a serpentine belt in its last hours of life, but there are many other belts which may also be the culprit. Belts which power many other devices including water pump, power steering, air conditioning compressor, and alternator. A screeching belt will eventually break and leave you stranded. Fix this if you want to use your vehicle to get you from point A to point B.

3. Squeaky brakes

When your brakes are screaming at you every time you use them, the brake pads or shoes are at the expiration date. The screeching comes from a tab of metal built into the pad that becomes exposed as material wears away. If you do not replace the pads or shoes and this noise goes away, head to the service department today because a new noise will begin…

4. Grinding noise

Now the squeaky brakes have stopped, but you haven’t fixed them. The next sound will be a powerful grinding sound which means the last of the pad has ground away and the metal backing plate is now pressing directly onto the brake disc. Your safety has now been compromised because trying to slow down your car will be less effective. The repairs will now be more expensive now because the discs will have to be replaced as well as the pads and or shoes.

5. A loud sucking sound

When you’re at a gas station and begin filling up your gas tank, you may hear a sucking sound coming from your vehicle. This is due to a gas guzzling monster that is your vehicle, slowly sucking your bank account dry and replacing it with empty fumes. Do yourself a favor and visit us at toyotaoftheblackhills.com and find a gasoline sipper. It will definitely save you money down farther the road.