What Is the Meaning of the Tire Size Numbers?

If you’ve ever taken a close seem at your tires, you’ve witnessed a collection of figures embossed on the tire. Whilst these can appear mysterious, they are truly employed to label a series of specs about the tire, also identified as the tire provider scores. So, what do tire figures imply? Let’s break it down.

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What Do Tire Numbers Mean?

The placement of the quantity or letter on the tire decides what is described. For this case in point, we’ll be likely by these quantities on a typical tire: P 215/sixty five R 15 89 H

michelin tire
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Tire Service Ratings:

  • 215: the three-digit number following the first letter describes the tire width in millimeters.
  • 65: Separated from tire width by a forward slash, this number refers to the tire’s aspect ratio, which is how tall the tire’s sidewall is. The aspect ratio is a percentage of the tire’s width. So, in this case, the tire’s sidewall is 65% of the tire’s width. If you convert the sidewall height to inches (215 millimeters = 8.46 inches) and then multiply it by the aspect ratio, you get a sidewall height of 5.5 inches/139.7 millimeters.
  • R: this letter tells you the tire’s construction type. In this case, R means radial, which is the standard for most vehicles. Radial tires have strong, coated cords laid perpendicular underneath the tire surface to the direction of travel. Other letters you may see are D for diagonal and F for flat-run tires.
  • 15: this two-digit number describes the wheel diameter in inches. Specifically, it’s the distance between the bead seat areas.

How to Tell if a Tire Will Fit Your Car

close up tires
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If you’re intrigued in buying otherwise sized tires, you ought to first examine if they’ll match your car. The greatest way to find out if a tire will fit your auto is to merely inquire a tire specialist. They are educated to measurement tires for different makes and versions of automobiles and will know what kinds of tires are compatible with your vehicle.

Tire dimensions distinctions could trigger cosmetic body injury or interfere with your car’s suspension or brakes. Differences in the tire pace index or load index can have an effect on how your vehicle rides, your successful leading speed, and how a lot excess weight your tire can manage.

car and road dividerConclusion

The letters and figures on your tires may seem inscrutable and arcane, but they in fact refer to different specification scores about your tire. It is essential to hold these in head when you have your tires changed due to the fact not all tires are suitable with all autos.

Highlighted Impression Credit score: RitaE, Pixabay