Wheels and Tires

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You might be wondering what some of the questions could be. Here's a list of what you should think about before entering a tire store.

1. Tread life considerations: What's your idea of how long a set of tires should last? Keep in mind that in some instances, a tire's wear rating is done through manufacturer testing and may not be the most accurate representation of a tire's true life expectancy. One way to get a handle on a tire's projected life expectancy (besides what they're warranted for, say, 40,000 miles for example) is to look at part of the UTQG (Uniform Tire Quality Grading) rating. The U.S. Department of Transportation requires each manufacturer to grade its tires under the UTQG labeling system and establish ratings for tread wear, traction and temperature resistance. These tests are conducted independently by each manufacturer following government guidelines to assign values that represent a comparison between the tested tire and a control tire. While traction and temperature resistance ratings are specific performance levels, the tread wear ratings are assigned by the manufacturers following field testing and are most accurate when comparing tires of the same brand. Tread wear receives a comparative rating based on wear rate of the tire in field testing following a government specified course. For example, a tire grade of 150 wears 50 percent longer than a tire graded 100. Actual performance of the tire can vary significantly depending on conditions, but the tire's UTQG tread life number can help you get in the ballpark as to how long a tire will really last.
2. Wet weather requirements: Most of us live in a climate where inclement weather is a factor at least part of the time. Clearly if you live in, say, Washington or Oregon, you'll want to look more closely at a capable wet-weather tire than if you're in Arizona or Nevada. For those of you in Snow Belt states, some kind of four-season type of tire will be the minimum you should consider if not an all-out snow tire for the winter that you swap for standard tires in the milder months.
3. Speed rating: Even in the plains and Western states like South Dakota, Nebraska, Idaho, Montana, New Mexico, Colorado, Wyoming, Utah, and Nevada where the rural interstate speed limit is 75 mph, how often do you think you're going to need a tire that's speed rated for anything over 150 mph? Be honest and knock down your required speed rating to, say, and H-speed rated tire that's still good for 130 mph. You'll pay less and likely not notice the difference in the real world. For reference, the most common speed ratings you'll come across on the majority of tires are shown in the chart below. Speed ratings signify the safe top speed of a tire under ideal conditions. For just about any street car, a V-rated tire will be more than adequate, unless the car will actually go faster than 150 mph. Usually, most ultra-high performance handling tires have a speed rating of at least V, so while you might want the ultimate handling of that type of tire, be aware that part of what you're paying for (the speed rating) is something you'll never use. For those who want tires that make a car really stick in the twisties, it ends up that many get the speed rating anyway, even though they don't need it. That's not a bad thing, but also be aware that tires with higher speed ratings are usually made from a softer rubber compound and generally will have shorter UTQG tread life ratings and, furthermore, will not actually last as long in the real world.

   Q= 99 mph
   S= 112 mph
   T= 118 mph
   U= 124 mph
   H= 130 mph
   V= up to 149 mph
   Z= 149 mph and above
   W= 168 mph
   Y= 186 mph

4. Ride Quality: A low-profile tire such as a 50 or a 40-series looks great, but can be harsh over bumps or potholes when compared to a 55 or 60. In general, a lower profile tire also exposes the wheel to damage more easily. Lower profile tires also have stiffer sidewalls, which improves handling but increases rides harshness. It's all about compromise and there's no such thing as a free lunch.
5. Noise: Some tread designs are noisier than others and it varies significantly between tire brands and tread designs. If most of your driving is on lower-speed city streets, then this won't be much of a factor. But for highway driving, you'll want to consider your options, especially if you're driving an SUV on pavement most of the time. A good salesperson will be able to tell you which tires are quieter among those you're considering; even those of the same make that are in a different line can vary in road noise.