Interpreting What's written on your Tire

UTQG Rating:

The Department of Transportation requires each manufacturer to grade its tires under the Uniform Tire Quality Grade (UTQG) labeling system and establish ratings for tread wear, traction, and temperature resistance. These tests are conducted independently by each manufacturer following government guidelines to assign values that represent a comparison between the tested tire and a control tire. While traction and temperature resistance ratings are specific performance levels, the tread wear ratings are assigned by the manufacturers following field testing and are most accurate when comparing tires of the same brand. Tread Wear Tread wear receives a comparative rating based on wear rate of the tire in field testing following a government specified course. For example, a tire grade of 150 wears 1.5 times longer than a tire graded 100. Actual performance of the tire can vary significantly depending on conditions, driving habits, care, road characteristics, and climate. Traction Straight-a-head wet braking traction has been represented by a grade of A, B, or C with A being the highest. In 1997 a new top rating of "AA" has been introduced to indicate even greater wet braking traction. However, due to its newness, this grade will probably be applied initially to new tire lines as they are introduced and later to existing lines which excel in wet braking, but had been limited to the previous top grade of "A". Traction grades do not indicate wet cornering ability. Temperature Temperature resistance is graded A, B or C. It represents the tire's resistance to the heat generated by running at high speed. Grade C is the minimum level of performance for all passenger car tires as set under Federal Motor Vehicle Safety Standards. This grade is established for a tire that is properly inflated and not overloaded. Note: UTQG ratings are not required on winter and light truck sized tires.

* Other acronyms that may or may not be directly written on your tire but have meaning in the Tire Industry, which include:

W or WW - WhiteWall
B or BW - BlackWall
RWL - Raised White Letters
OWL - Outlined White Lettering
ORWL - Outlined Raised White Letters
LT - Light Truck

Load indexing and Load range:

The newer system for rating tires includes load indexing. The "load index"? is an assigned number that corresponds with the load-carrying capacity of a tire. Most passenger car tire load indexes range between 75 and 100. A few examples are as follows:

www/aaCrr LiS- (ex. 225/60R15 92H)

92H - 92 Load Index rating = 1389 lbs, (H = Speed Rating)

Other random Load Index numbers:

85 - 1135 lbs
88 - 1235 lbs
91 - 1356 lbs
95 - 1521 lbs
100 - 1764 lbs

Tires can also be listed with a load letter indicator, mostly associated with Light Truck tires, such as: LT245/75R-16/C. This type of rating is based upon the tire inflation rate. The higher the inflation pressure, the higher the load-carrying capacity. Depending upon the tire size, construction and inflation rate, the follow load ranges apply.

Load Range C = anywhere from approximately 980 lbs capacity to 2910 lbs.

Load Range D = anywhere from approximately 1589 lbs capacity to 3415 lbs.

Load Range E = anywhere from approximately 1915 lbs capacity to 3525 lbs.

Load Range F = anywhere from approximately 3720 lbs capacity to 4080 lbs.

Example: Load range for LT245/75R16/C or /D or /E in lbs.

TIRE ROTATION

In this day and age of high speed travel , highway mileage, stop and go traffic, you are lucky your tires are not worn out after just 15,000 miles! In order to prolong the useful life of your tires, they need to be rotated regularly.

Tire manufacturers highly recommend that your tires be rotated every 6,000 to 8,000 miles or at any evidence that your tires are wearing unevenly. Of course, before you rotate your tires, you should consult your vehicle's owners manual for tire rotation recommendations. If the manufacturer does not recommend any specific mileage interval, use the 6-8,000 mile rule of thumb.

Rotating your car tires will help evenly distribute the amount of wear on each tire and extend the life of the entire set of tires. You should be aware of a few key bits of information before you start moving tires around. Some kinds of tires can not be rotated in the recommended, front to back or cross corner pattern. These are tires that are; uni-directional or have asymmetric tread designs (usually tires that are designed specifically to be only a right or left) or tires of different sizes (as in some automobiles, the front tire sizes may vary from the size of the back tires).

Once you have determined that you are able to rotate your vehicle tires, you then should pay attention to the inflation pressure. The air pressure in each tire must be adjusted for the tires new position on your vehicle. Follow the vehicle manufacturers recommended air pressure setting to ensure what the correct inflation level is for your vehicle. If you do not, improper inflation rate can lead to premature tread wear, increased fuel consumption, poor handling and performance. You can check the proper pressure by using a standard tire pressure gauge.

Some other things to be aware of:

-  Make sure ALL of the tires are the same sizes, construction and speed rating. If there is a difference in tire speed ratings of the tires mounted on your vehicle, the lower rated tires will reduce the performance and handling of your vehicle.

-  Make sure tires of the same construction and make, are located on the same axle?.

-  If there is a mix of radial and non-radial tires, make sure to put the radials on the rear.

-  Snow tires should be put on your vehicle in pairs on the drive axles (for either front wheel or rear wheel drive vehicles). Never put non-radial snow tires on the rear of your vehicle if radials are used in the front. If you used studded tires on the front axle, you should use studded tires on the rear. It is recommended that snows or all season tires be used on front wheel drive or performance vehicles for better handling in snow conditions.

-  Ensure that ALL tire sizes and construction are exactly matched up on four-wheel drive vehicles.

The following diagrams depict the recommended tire rotation patterns for passenger and Light Truck vehicles.