Knowledge Center
Before you decide on a new tire, ask yourself these questions:
What tires are on your car now?
Did you like your old tires? (traction, smooth ride, good handling, Long wearing, etc.?)
What do you want your new tires to do? (high miles, more traction, etc)
How important is crisp handling and quick stopping compared to smooth ride or long wear?
What kind of “look” are you after?
What level of convenience, service and warranties do you expect?
When you answer these questions, you narrow the choices to ones that fit your specific needs and wants. It helps the salesperson, too. He or she won’t waste your time discussing tires you don’t want.
Determining your correct tire size
Look in your automobile owner’s manual. You’ll find the size fitted on the car originally. Unless you’ve changed wheels, that’s the recommended size. The tire size is written on the tire’s sidewall.
Reading the tire sidewall:
“P” indicates a passenger (car-type) tire. Other options would be no “P” indicating metric sizing (essentially the same as “P”-sizing, which has its heritage in Europe) or “LT” for light truck. Light truck tires are designed for heavier loads and more rugged service conditions. Width of the tire in millimeters: The higher the number the wider the tire. Aspect Ratio: The height of the sidewall section compared to the width of the tire.
Example – Tire sizing as it appears on the sidewall: P215/65R15 89H
P — Passenger car tire LT — Light Truck
215 — Width of tire in millimeters
65 — Ratio of height to width (aspect ratio)
R — Radial D/B — Bias Construction of Plies
15 — Diameter of wheel in inches
89H —Load index & Speed/Performance Symbol
Now the speed symbol
Each letter corresponds to a speed rating on an indoor test wheel:
N = 87 mph
P = 93 mph
Q = 99 mph
S = 112 mph
T = 118 mph
U = 124 mph
H = 130 mph
V = 149 mph
Z = 150+ mph
W = 169 mph
Y = 188 mph
We recommend that the replacement tires match the speed symbol of the original tires since these match the speed capability of the vehicle.
Uniform Tire Grading (UTQG)
The Uniform Tire Quality Grading (UTQG) is a system developed by the Department of Transportation which helps consumers compare tires in the areas of treadwear traction and temperature.
Example – A tire with a UTQG of 300 AB: The 300 is treadwear, which represents the tire’s comparative wear when measured against the government-mandated tire which is rated at 100. So this tire wore three times longer than the control tire.
Because of variations in operation conditions, the treadwear grade cannot be used to predict actual wearout mileage. It can be used to predict the relative wear rate of tires with different UTQG wear rates.
Traction and temperature are graded A (superior), B (good), or C (average). Traction indicates the level of grip the tire possesses. Temperature rating deals with the tire’s ability to disperse built-up heat. Heat causes rubber to deteriorate over time, so dispersing heat increases tire life.
Each tire manufacturer determines UTQG rating for their products. Realize that UTQG’s are more accurate when comparing tires within the same line versus tires from two different makers.
Tire maintenance
Inspect your tires regularly. Properly cared-for tires typically last 40,000 to 80,000 miles, depending on the application. Practice good driving habits, which will help keep your tires in good condition. Your tire maintenance checklist includes:
Pressure
It is important to have the proper air pressure in your tires, as under inflation is the leading cause of tire failure. The right amount is specified by your vehicle manufacturer and is also listed in your owner’s manual.Alignment
Misalignment of wheels in the front or rear can cause uneven and rapid treadwear. Have your alignment checked periodically.Rotation
Sometimes irregular wear can be corrected by rotating your tires. Consult your vehicle owner’s manual or your tire dealer for the appropriate rotation pattern for your vehicle.Tread
Tires must be replaced when the tread is worn down to 1/16″ in order to prevent skidding and hydroplaning.
Open and Closed Shoulder Tires: An Informative Overview
Tire/tread design plays a crucial role in vehicle performance, safety, and comfort. Among various tire characteristics, the shoulder design—whether open or closed—significantly impacts handling, traction, noise levels, and wear patterns. Understanding the differences between open and closed shoulder tires can help drivers choose the right tires for their specific driving needs.
The shoulder of a tire is the area where the tread meets the sidewall. Essentially, it is the outer portion of the tread on each side of the tire that contacts the road. Tire manufacturers design the shoulder with specific patterns that influence how the tire manages water, slush, snow, or mud as you drive.
