When selecting a tire most people depend on the expertise of the local tire dealer. If the tire dealer suspects someone doesn't know the first thing about tires, they may sell a tire that’s not the best choice for the vehicle. Before talking to a tire dealer, being prepared with some basic tire information will help select the best tire value.
Most of the basic information needed before visiting a tire dealer can be found on the sidewall of the old tires. Below is a list of information that can be found on the sidewalls. If the old tires are original from the factory, the information found on the sidewall should match with the replacement tires.
Tire Size
The tire size can be found on the sidewall of the old tire. Taking note of the tire, do some price comparisons on the Internet before visiting a tire dealer.
P205/60R16 is an example of a tire size as it appears on a sidewall.
- P stands for passenger tire; an LT would mean a light truck tire.
- 205 is the width of the tire in millimeters, the higher the number the wider the tire.
- 60 is the ratio of the width of the tire to the height of the sidewall. In this example the sidewall height would be 60% of 205 millimeters. A lower ratio would result in a lower sidewall height.
- R simply means that it’s a radial tire.
- 16 is the diameter of the wheel in inches.
DOT Quality Grades
Every new tire has a label attached that shows the quality grades as mandated by the Department of Transportation (DOT). To insure a good value on a tire, it's important to ask the tire dealer what the DOT quality grades are of the tire they suggest. There are three quality grades that will determine the quality of a tire.
- Treadwear. The quality of the treadwear is expressed in hundreds. This gives a good indication of how long the tread of the tire will last. The higher the treadwear number, the longer the tread life of the tire.
- Traction. The traction quality grades are listed as AA, A, B or C, where AA is the best and C is the worst. The traction quality grade is the ability of the tire to stop on wet pavement.
- Temperature. Temperature is listed on the tire label as A, B or C, with A being the best. The temperature quality rating represents the tire’s resistance to the generation of heat and the ability of the tire to dissipate heat. Heat can cause a tire’s material to deteriorate and reduce a tire’s life. Sustained heat can cause premature tire failure.
Speed Rating – Load Range
The speed rating of a tire usually follows the tire size on the sidewall and is expressed as a letter. The speed-rating letter will follow the load range on a passenger tire. Load range on a passenger tire is normally not a concern when purchasing a tire. Speed ratings can be a bit confusing. To get a better understanding of speed ratings take a look at this speed rating chart.
For light duty truck tire’s there's a load range listed on the sidewall. Other than commercial trucks, the normal load ranges are C, D or E, with E load range carrying the heaviest load. Whatever the current tire’s load range is, it's normally acceptable to buy a tire with the same load range. If the truck's tires carry a lot of heavy loads or tow a heavy trailer, consider going to a higher load ranged tire.
How Old is the New Tire?
The DOT mandates that every tire carry an industry standard code. The DOT code can pinpoint when and where a tire was manufactured in case a tire is recalled for quality issues. The DOT code can be found on the sidewall of the tire and can be from 10 to 12 letters and numbers. The code on the tire is actually followed by the word DOT. The last four numbers of the code specifies when the tire was manufactured. For example if the code ends in 1809, the tire was manufactured in the 18th week of 2009.
Tire Care and Maintenance
Preventive tire maintenance is important for keeping the tires in top condition. As part of a routine vehicle maintenance, tire tread depth and psi should be checked nd maintained. There are are also different types of tires that may be considered for various road conditions like winter tires or all-terrain tires.
In summary when selecting a tire, first get the tire size and compare prices on the Internet. Next ask the tire dealer what the DOT quality ratings are of the tire they suggest. Last, make sure the speed rating or load range is correct.
