Radial Care: How to Choose and Use

Jim Luff
Posted on August 14, 2009

The practical primer on tire care goes like this: Learn how to determine the correct tires for your vehicles, what the numbers on the sidewall mean, what you can fill the tires up with besides air, how to inspect your tires, and tell when to replace them.

Inspect Tires Daily

A quick visual inspection can tell you a lot about your tires and your suspension system, but it will not tell you if they are properly inflated. The only way to see if the tires have enough air is with a quality air pressure gauge. Don't rely on the gauges on service station hoses as they are rarely calibrated and inaccurate. When inspecting tires, check for even tread wear first. Abnormal tread wear may indicate your tires are not properly balanced, your vehicle is out of alignment, or your tires are not properly inflated.

Looking from the inside to the outside, the tire should be smooth and level all the way across when running your palm on the surface. Vibrations at certain speeds or steering wheel shakes indicate your tires are not balanced. The surface will become "cupped" and it will be felt in the palm of your hand. A vehicle "pulling" to the left or right is probably out of alignment. The constant tug on the steering wheel will cause uneven tread wear on the inside or outside edge of the tire.

Once a tire becomes severely worn in an uneven pattern, it must be discarded. That could be costly if not caught early. Over-inflated or under-inflated tires also can ruin tread that needs to be replaced prematurely. Under-inflated tires will break the sidewalls down, cracking the sidewall, while over-inflated tires will wear down the center of the tire. If your tires have any cracks in the sidewall, bulging, or discoloration, you should replace them immediately.

Regular rotation of your tires can extend their life. Worn shock absorbers also can cause excessive wear on your tires, so be sure to inspect and change them as often as the manufacturer suggests or when worn.

Selecting Proper Tires

The manufacturer of your car is federally mandated to provide a recommendation about the size and type of tires best suited for your vehicle on a placard on your vehicle. You may find this attached to your door edge, door post, glove compartment door, or inside your trunk lid.

Understanding the numbers on the sidewall will help you determine the best tires for you as recommended by the manufacturer. The numbers are standardized by federal law. Tires also have different types of tread patterns and are referred to as All Season, Touring, Grand Touring, Performance, and Snow or Winter tires.

The All Season tires offer the longest tread and are suitable areas without much bad weather. Touring tires offer better handling and a quieter, smoother ride, but cost more than All Season tires. Grand Touring offers an even higher level of comfort. Of course, Winter tires are made to handle harsh winters and are removed after winter has passed.

Make sure you buy a complete matched set of tires for your vehicle. Installing a matched set provides a better ride and will allow you to clearly identify problems with your tires.

Where to Buy

Just as we sell service over price, there is great value in finding a local tire dealer to work with regularly. Whether it is a national chain such as Firestone or Goodyear, being a regular customer can bring a higher service level as well as free flat repair, free rotations, and even roadside service.

Consider the services offered by your local tire dealer and ask about a wholesale account or commercial account for discounts based on volume. Your tire dealer can perform alignment services, oil changes, shock inspections, and other mechanical services on the suspension system of your vehicle.

There are many Internet based tire dealers such as,, and, which offer deep discounts on tires shipped to you. What you may save in the price of the tires might be offset by the cost of installation in some cases, so know who will mount your tires when they arrive and what it will cost to factor this in.
Of course, private clubs such as Costco generally sell tires and perform installation at discount prices.

Where to Buy Tires

  • Local tire dealer
  • Online tire dealer
  • Discount clubs such as Costco

Inspecting Your Tires

  • Always use a quality tire pressure gauge
  • Inflate to the manufacturer's recommendation while cold
  • Check for even tread wear from inside to outside
  • Run your palm over the surface checking for smoothness
  • Check for "cupping" or "rounding" indicating a problem
  • Check for sidewall cracks, discoloration or bulging
  • Check for nails or other imbedded items

Air or Nitrogen?

In an effort to improve mileage, some operators have begun using nitrogen to fill their tires instead of air. It appears the jury is still out on the benefits of one versus the other in a recent non-scientific survey conducted by LCT. George Bourque of Fairfield, Maine, is using pure nitrogen and said he enjoys a 1 to 1.5 mile-per-gallon increase since he began filling his tires with nitrogen.

According to NASCAR officials and Goodyear, nitrogen-filled tires maintain tire pressure longer and resist heat buildup at 200 mph. This is probably not a buying consideration for the livery industry.

Only about 10% of all tire dealers nationwide carry nitrogen, according to Modern Tire Dealer Magazine. But Costco has jumped onboard as a convenient place to purchase nitrogen at about $5 a tire. The good news is once you have them filled, most locations offer free refills.

On the technical side, nitrogen molecules are bigger than oxygen molecules, so nitrogen seeps out more slowly from tires than air; nitrogen resists heat buildup better than air, which contains moisture; and nitrogen reduces oxidation, which can damage the tire from the inside out, proponents say.

The National Highway Traffic Safety Administration said it has no opinion on nitrogen and neither do tire experts at Consumers Union, publisher of Consumer Reports magazine.

If you choose to stay with the air we breathe for your tires, avoid airing up tires at coin-operated pay stations. Try a traditional service station that uses the same compressor to run its tools. Stale compressor air from infrequently used air stations can develop water and cause condensation to occur inside your tire, causing rot to occur. You should not be able to see a visible vapor from an air nozzle.

Related Topics: maintenance, tire pressure gauges

Jim Luff General Manager
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