Tire Tips

Tire Safety and Maintenance

You should check each tire's air pressure (including spare) once a month and always before a long trip. Always check when they are "cold". At least three hours after the vehicle has been stopped, or before it has been driven one mile.

Load carrying limits, molded into the tire's sidewall, should never be exceeded. Consult a trained tire professional to verify limits for the tire you have chosen.

If for some reason you cannot safely avoid a road hazard and you run over glass, rocks, curbs, or other foreign material, check the tire for external damage. If you suspect damage but can't see it, have the tire demounted and checked for internal damage by a trained professional.

The simplest way to check tread depth is to place a penny into the tread (Lincoln's head first). If the top of his head remains visible, the tire needs replacing (less that 1/16").

Having your tires regularly rotated achieves more uniform wear on each tire. If no rotation period is specified in your owner's manual, then the tires should be rotated every 6,000 to 8,000 miles.

If you get stuck in mud or snow, don't spin the tires to get out. Spinning, even for a few seconds, can build up heat and damage tires.

Properly balanced tires and wheels turn with all their weight distributed equally. Unbalanced tires can result in a vehicle's shimmying (shaking from side to side) and tramping (hopping up and down).

Cleaning tires removes foreign substances that can degrade the tires. Remove the substances from the tires. Soap and water are recommended.

Check your tires at least once a month for uneven wear and foreign objects wedged in the tread. A tire that continually needs more air should be taken off the vehicle and off the wheel and checked thoroughly.

Tips for Proper Inflation

Purchase an accurate pressure gauge, as it's impossible to tell how much air is in a tire by looking at it. The gauges attached to air hoses may not be accurate. It is normal for all tires to lose air over time.

The pressure should never be below the recommended pressure listed on the vehicle placard nor above the maximum branded on the sidewall of a specific tire under normal driving conditions.

What to Look for in Choosing a Tire

Buy the correct size tire. The appropriate tire size for your car can be found in the owner's manual or on a placard located somewhere in the vehicle. Also, consider the car's original equipment when purchasing a replacement tire.

Consider factors such as load-carrying capacity of the tire, as well as traction, treadwear and temperature grades, also known as the Uniform Tire quality Grade System.

When tire shopping, keep in mind that there is a difference between the lowest price and the best value. As a consumer, finding the highest quality tire that will fulfill your specific needs at the most competitive price should be the ultimate goal.

When purchasing a tire, be sure to fill out and mail the DOT Tire Registration Card so you can be notified of any product updates.

Uniform Tire Quality Grade [UTQG]

Each tire manufacturer is responsible for designating the rating of each of its tires. LT designated light truck tires do not have UTQG markings. The Uniform Tire Quality Grade offers three key pieces of information about a tire:

• Treadwear grades - typically range from 60 to 620 in 20 point increments. The higher the grade the longer the tread life.
• Traction grades - indicate a tire's braking performance. A grade from "AA" to "C" is assigned, with "AA" signifying the best traction.
• Temperature grades - represent a tire's ability to withstand heat under test conditions. Temperature grades are assigned "A" to "C" with "A" signifying the most resistance to heat.

Sidewall Markings

Much of what you need to know about a tire can be found on its sidewall. Each letter and number of the alphanumeric code found on the sides of any tire conveys important information, like whether a particular tire will be compatible with you vehicle. Some size designations are preceded by a letter indicating the type of service for which the tire is intended.

DOT Markings

DOT marking serves as the tire's fingerprint and signifies compliance with U.S. Department of Transportation Tire Safety Standards. For example - DOT M5H3 459X 069

The first two characters, M5, designate the tire's manufacturer and plant code. The third and fourth characters denote the tire size. The fifth, sixth, seventh and eight (optional) characters identify the brand as well as other significant characteristics. The final three numbers (four beginning in 2000) denote the date the tire was produced, with the first two indicating the week and the last number indicating the year (069 indicates the tire was built in the 6th week of 1999).

How to Read a Sidewall

Just what do all those letters and numbers on a tire's sidewall mean anyway? The look like some sort of secret code! Actually that's not a bad way to think of them. The numbers located on the tire's sidewall are used by tire manufacturers and the Department of Transportation (D.O.T.) to convey important information about tire size, speed rating, maximum load carrying capacity and more. Click here for more information about the 'Uniform Tire Quality Grading System'.

Uniform Tire Quality Grading System Database Lookup

The National Highway Traffic Safety Administration maintains a tire quality grading database.

Visit the NHTSA at ntl.bts.gov/faq/tires.html to search the database.