F.A.Q’s About Buying New Tires?

What Should I know before I buy New Tires?
tire_stackWhen you are shopping for tires the first thing you need to do is determine the size of the tire you need. This information is on the sidewall of the tire you are going to replace. The tire size will be written as P235/60R16.

Don’t panic if you don’t know what all of this means, we’re here to help!

The “P” indicates that the tire is a passenger car tire. The 235 says that the tire tread is 235 millimeters in width. The 60 means the tire’s height is 60% of the tire’s width. The “R” means it’s a radial tire and the 16 indicates the overall wheel size in inches. So a P255/60R15 is wider and shorter than a P215/75R15. Also written on the sidewall will be maximum load as well as inflation information and speed ratings*. ( *Performance Tires Only ).

To allow you to compare tire brands, there is three other ratings written on the sidewall of the tire. The first one is likely to say “Treadware” and then a number such as “300”. The higher number is, the longer the projected tread life is under optimal conditions. NOTE: Driving style, road conditions, alignment, rotation, and air pressures and heat can affect a tire’s life expectancy.

For comparison purposes, the index used by tire manufactures is a percentage grading based on 100. 100 being average for the base tire in that manufacturers line. For example, a treadware rating of 150 from company “X”, means that tire will wear 1-1/2 times as well as a tire from that company with a rating of 100 when all of the driving conditions are constant.

As another example, B.F. GOODRICH Radial T/A HR4’s have a rating of 310 and the B.F. GOODRICH Comp T/A HR4 has a rating of 340. This means that the Comp T/A HR4 should last 1.096 times as long as the Radial T/A HR4.

245/45ZR/17 - Kumho ECSTA Supra 712For most of us, the actual tread-wear warranty is easier to work with. It is the amount of miles you can expect to drive before you will have to replace that tire when it is properly maintained. Many tires carry a 40,000 mile warranty, which translates to an treadware rating of approximately 360. Another way to compare this rating is to take the number, in this example “300”, and multiply it by 2 and add 2 zeros. the number would turn into 60,000. Which can be figured to be the approximate life of the tire.

The second rating is written as “Traction”. This is a rating of either A, B or C with A representing the best grade a tire can receive for it’s traction abilities. A mud and snow tire or an all season tire will almost always have an A rating. A highway or high-speed tread could have a B or a C rating.

The third rating will be written as “Temperature”. This rating represents the tire’s ability to stand up to high temperatures. An “A” rating is the highest grade and “C” is the worst.

*Speed Ratings are designated on Performance tires to indicate the top speed for which a tire is certified. It does not indicate the total performance capability of a tire. (Speed Ratings Chart)

•What Should I know before I buy Larger Wheels and Tires?
When you are shopping for new wheels the biggest concern is to make sure that they will fit you car properly. If the wheels are to big the tires will rub. If the offset of the wheel is not right, it will stick out beyond the body or rub on the chassis or steering components causing component or tire failure. One other problem is that your speedometer will be off if you change the circumference of the tire. A tire that is of a larger circumference (outside diameter) will make the speedometer read slower. A smaller tire will make it read faster. To be sure that your speedometer reads as close as possible, use the “Tire Size Calculator below.

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