Performance Tires - Tire Anatomy 101

The Inside Story On Performance Tires

Shane Reichardt Jun 1, 2000 0 Comment(s)
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This cutaway of a Yokohama A520 shows how the tire is constructed. Though various tire manufacturers use special features in their products, the basics are usually similar.

Tires--they're round and made of rubber. What else is there to know about them? Plenty! Save for a few die-hard restorations, most performance enthusiasts will change the tires on their classic to something other than what was standard equipment. Choosing the right tires for your performance driving habits and conditions can be a confusing process, to say the least. Walk into any tire retailer and you're sure to be overwhelmed with a wide array of options. Which is right for you? Well, many enthusiasts will go with a popular tire because their friends are using them, or they'll stick with a particular brand because it's always worked well for them in the past. The reality is that there are probably a dozen or more tires that will suit your needs, but finding them isn't easy.

Knowing the size is the easy part. Determining your needs and the environment you will be driving in will help reduce the number of tire choices. If you live in (and will do most of your driving in) a wet environment, tires designed for rain will be a big help in keeping the rubber side down. Someone living in the deserts of Arizona may not care about the wet handling capabilities of their tires. In some areas it might be a good idea to have a set of tires for summer and another set for the wet winter months.

If you only drive your car short distances and most of that is to and from the drag strip, you should consider one of the DOT-legal drag tires that are currently available. A number of high-performance tire companies like BFGoodrich and Mickey Thompson have begun to offer these, and they are a great alternative to changing wheels and tires when you arrive for a race.

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The Toyo RA1 is a DOT-legal racing tire. It is designed for grip in the corners as well as on the straightaways. Tires intended for racing but legal for the street will often have limited treadwear, as is the case with this tire, which shows a 40 in the UTQG treadwear listing. It's a great tire, but don't expect a long life driving it on the streets.

One thing we found while researching this story is that almost every tire manufacturer has a website with enough information to boggle nearly any mind. With an Internet connection, you can do a great deal of research on various tire designs, compounds and, hopefully, find the perfect tire for your driving needs. If surfing the Internet isn't an option, try finding a local tire retailer with a large selection and a knowledgeable staff.

Basics
We all know that tires are made of rubber, but did you know that different tires use different rubber composition? From harder compounds built for high mileage to softer materials designed to "stick" to the road, there is a lot of technology that goes into creating a specific tire.

This information can be read in the tire ratings or the UTQG (Uniform Tire Quality Grade). These letters and numbers tell you the wear, traction, and temperature characteristics of a tire. Usually, achieving high performance in one area means a trade off in another area. For instance, a high-traction tire with a softer compound will typically has a shorter life span (poor wear). The wear charistics of a tire are listed as a numerical value, with 400 being the highest. Toyo's Proxes T1-S has the highest traction and temperature ratings and a wear rating of 280. The Toyo Proxes RA1 have a wear rating of only 40, mainly because they are hard-core road racing tires. BFGoodrich's drag radials, on the other hand, list an extremely high traction number but have no listed durability because their ultra-soft (sticky) compound isn't intended for use as an every day driving tire.

Temperature grades range form A to C, with A being the highest. Temperature grades represent a properly maintained tire's ability to dissipate heat under controlled indoor test wheel conditions.

Tire pressure is another important factor in tire performance and longevity. Proper air pressure should always be read while the tire is cold (preferably after it has been sitting for eight hours). Proper tire pressure will ensure the tire makes the best contact with the road-better contact, better traction. Under- and over-inflation are also big causes of wear on tires. To find the correct tire pressure, consult the tire manufacturer and/or vehicle manufacturer recommendations. One thing to remember, though, is that the best pressure isn't what is listed on the sidewall of the tire. This is simply the maximum tire pressure. Tire pressure should be set for your vehicle's weight or load.

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