When researching tires and comparing your options there are a few things to take into consideration. Not all tires are the same. They can come in different sizes and have varying tread-wear, traction, temperature and speed ratings. Infiniti recommends that you only replace your tires with tires that have the exact same ratings as the tires that came factory installed on your vehicle. Doing this will help to ensure safety, optimal fuel economy and ride comfort as Infiniti intended for your vehicle to have.
Size
Tire sizes are a combination of several variables: the actual size in width, height and diameter, and then the ratings related to load-carrying capacity and speed-handling ability. Make sure to consult your vehicle’s owner’s manual to find the correct tire size, or check the metal tag found inside the driver’s door, glove compartment or fuel opening. Look on the sidewall of your tire instead if there are multiple sizes listed.
Uniform Tire Quality Grading (UTQG)
The U.S. government has designated the Uniform Tire Quality Grading System (UTQGS) to help you decide which tires you should purchase. It is a comparison system, not a safety rating and not a guarantee that a tire will last for a prescribed number of miles. Under UTQGS, tires are graded by manufacturers in three areas: treadwear, traction and temperature.
Treadwear
The tread-wear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test track. A tire graded 200 would last twice as long on the government test course under specified test conditions as one graded 100. It is an oversimplification to assume tread-wear grades will be proportional directly to your actual tire mileage. The relative performance of tires depends upon the actual conditions of their use and may vary due to driving habits, service practices, differences in road characteristics and climate.
Traction
Traction grades, from highest to lowest, are AA, A, B and C. They represent the tire’s ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. The testing does not take into account cornering, hydroplaning or acceleration.
Temperature
The temperature grades, from highest to lowest, are A, B and C. These represent the tire’s resistance to the generation of heat.
Speed Rating
Speed rating is based on how well a vehicle reaches and sustains a specific speed. The US Government issues each vehicle a speed rating. A high speed rating means that the tire will provide better handling. The testing measures high speed tire durability under controlled conditions.