The Motor Vehicle Tire
Your tires are literally where the "rubber meets the road." No matter what tires you place on your vehicle, you want to ensure, most of all, they will provide enough traction to keep you and your family safe.
Tire Identification
Did you ever wonder what those raised marking on the side of a tire meant? For instance, on the outer sidewall of a tire you will see a raised set of numbers and letters -- something like, P205/70R15 85Q.
First, the "P". This letter describes the type of tire, and "P" translates to Passenger. Other common types would be "C" for Commercial, "LT" for light truck, and "T" for Temporary.
The 205 in our example is the tire's section width (refer to the image), and the 70 is the aspect ratio. The aspect ratio is the tire's height divided by the tire's width. In our example, the tire's height is 70 percent of the tire's section width.
The "R" relates to the tire's type of construction. "R" specifically means radial. Other common construction types include, "B" for bias belted, and "D" for diagonal.
The number 15 is the number of inches the rim should be to safely have the tire mounted.
The number 85 is the tire's load range. It is the amount of maximum weight that the specific tire should be loaded with. For example, a load rating of 85 means that the tire should safely support no more than 1,140 pounds. With four of this same tire, the total vehicle's weight, passengers and cargo included, should not exceed an aggregate of 4,560 pounds.
The letter "Q" in in the example is the tire's speed rating. Similar to the tire's load range, the speed rating is a speed at which the tire should not exceed. The letter "Q" would mean the tire should not exceed 100 miles per hour. Any speeds above that, and the tire may fail.
Tire Replacement
When is the right time to replace your tires? If a breach in the tire occurs in the side wall it is a best practice not to attempt to have it repaired. A side wall "hole" violates the overall integrity of the tire and could make it unsafe for operation at higher speeds and over rough roads.
When is your tire worn out? An old rule of thumb is the penny test. Place a Lincoln head penny in the tire's tread with Lincoln upside down in relation to the tire. If Lincoln's head is not covered by the tire then it is time to go tire shopping!
There are many tire makers bidding for your dollars, just some of the manufacturers are; BF Goodrich™, Goodyear™, Firestone™ Michelin™, General Tire™, Uniroyal™ and Kumho™.