When you take a look at the side of your tire it is likely that you have come across a few letters and a few numbers that don’t seem to fit with any design on the look of your tire. At the first glance, they may seem like a missing piece of the puzzle or a key piece of information. Here is what some of the numbers and symbols mean on the side of your tire:
P and LT
The P and LT values are the tire type. LT stands for a light duty vehicle. P designates that the tire is designed for a passenger style vehicle. ST may be found commonly on tires that are designed for use with special trailers.
The First Number of Three Digits
Following the letters that you will see on the sidewall of the tire will be a three digit number. This three digit number indicates the number of millimeters from one sidewall to the other. If you have a p205 tire for example, your tire width is going to be 205 mm.
The Two Digit Number
The two digit number is the aspect ratio or the ratio of the cross-section of the tire width. A rating of p205/70r will show that the aspect ratio is 70 meaning at the height it is 70% of the tire width.
Construction Type Letter
Some tires also have a construction site designating that they are radial, diagonal or run flat. R stands for radial, D stands for diagonal piles and F stands for a run flat tire.
The Second Two Digit Number
The second two digit number that can be found on your tire is going to be the wheel diameter. This is the size of the wheel from one end to another. This is usually measured in inches.
Last Digit of Readout
The last digit amongst these symbols is going to be the speed rating of your tire. This is the top speed that you can safely travel on this tire for extended periods. Most speed ratings on passenger cars are around 130 mi./h or 139 mi./h. The highest speed rating on a tire is a Y indicator for most passenger vehicles and this rates a tire that can support sustained speeds of 186 mi./h.
This post was written by Justin K, owner of Wheel Identity. Wheel Identity is Tampa Bay’s premier custom shop. We carry custom wheels in Tampa for every vehicle, custom suspension kits, and all accessories for the interior or exterior of your vehicle. We only hire highly trained technicians using state of the art equipment with experience in all areas of tire, wheel, suspension, and 4×4 needs.