How to Check the Softness & Hardness of Car Tires

by Danyel Bierly

Tires are manufactured in a rubber plant and the process consists of mixing a variety of chemicals into a large rubber block mold. Several batches of tires typically form with different grades of hardness within the same batch due to varying pounds and measures of the chemicals added to the mix. The most effective way to test the degree of hardness or softness of a tire is to use a durometer.

Place your bare hand on the tire to check to temperature.

Test your tire when it is at a neutral temperature. In order to do this you will need to test the tire in a covered area and when it has been driven for no less than two hours. Place your bare hand on the tire to ensure that it is cool to the touch.

Tire tread gives grip to your tire.

Place a penny into the groove of the tire tread to test the tread depth. If the tread comes up to the middle of the head of Abraham Lincoln then your tire will give an accurate reading. Low tread depth will give a low reading on your durometer.

Tires that are too hard do not grip well in turns.

Remove any dirt or stones from your tire by running the flat end of a scraper along the tire tread surface. This will remove any type of barrier that may come in between the durometer and the tire contact.

Use the flat end of the scraper.

Apply the base of the durometer to the tire using firm and even pressure. Do not tilt the durometer during the reading process as this will distort the final reading accuracy.

Test your tire air pressure regularly

Note the number that the durometer comes to quickly and stabilizes at. This will be your reading number. If you test another section of the tire, it should read the same. The durometer will measure from 0 to 99. If the number is low then the hardness of the tire is low. If the number is high then the harness is high.

Tip

  • check Remove the wrapper if you are testing a new tire.

Items you will need

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