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Tire Buying Guide

Getting ready to purchase tires for your car? Great! This tire-buying guide will give you all the information you need to purchase the right tires for your car and your lifestyle. From determining the right time to buy new tires, to making sure you pick the right size and type for your vehicle, the SimpleTire.com Buying Guide has you covered.

It's really that SIMPLE!

Q.When do I need to buy new tires?

Learning how to identify when you need to purchase new tires can be a daunting task. However, we hope to make that process a little easier. First, you must understand that it is important to check your tires at least once a month. The reason being is that you want to ensure that your tires are safe to drive on, or determine if they are in need of service or replacement. If you find that your tire is flat from a puncture from a nail or other road hazard, then there is still a chance the tires can be repaired. Your chances for repair or highest when:

  1. You have not driven on the damaged tire while it is flat.
  2. Any damage appears on the tread part of the tire (the area that comes in contact with the road)
  3. Finally, if the puncture is less than a ¼ inch.

If you feel your tire exhibits any of these conditions, contact your local auto service center immediately. They can tell you if your tire can be repaired or needs to be replaced. Remember, worn tires are not only unsafe to drive on; they are against the law. Legally the minimum tire tread depth is 2/32 inch. When the road is wet, 4/32 or less tread can mean a high risk of significant loss in wet traction. In other words, hydroplaning, which can put both the passenger and you at risk.

Below are the two most common ways to check for worn tires:

1. Penny Test

To test to see if your tread has been worn out, place a penny into the most shallow tread groove with Lincoln’s head facing down. If the top of his head is still visible, then the tire needs to be replaced.

2. Look for the wear bars

The wear bars are the narrow bands that appear in the grooves across the tread of the tire. When the wear bars are even with the depth of the tread, that means that only 2/32-inch of tread is remaining. If you are able to see the wear bars, then you tire needs to be replaced.

Q.How many tires do I need?

Once you have determined that your tires are in need of replacement you can now figure out how many tires to replace. Most people replace tires in sets of two or four. But it is possible for you to replace one tire (if you have a flat) or three tires as well.

When replacing one tire

You are going to want to find an exact match for the damaged or worn tire. That means you want to replace it with the exact brand, model, speed rating and load capacity. (Information about these items is in the next section) If you use a different tire than what was previously on there, you put your vehicle at risk for poor handling, pulling and instability.

When replacing two tires

You are going to want to replace with the same or better-quality tire. It is suggested that you buy two of the same tires when replacing. That way they should wear evenly and perform in line with one another. It is also suggested that you mount the new tires on the rear of the car (if rear wheel drive) or front of your car (if front wheel drive), and move the older tires to the front/rear of the car. This is because the newer tires have a deeper tread which helps with hydroplaning resistance so they can grip the road better than your older tires. You can then steer to compensate for the lower wet traction worn front tires to safely control your vehicle.

When replacing three tires

When replacing three tires, you will want to follow the same rules as replacing two tires. You will want to put the two newer tires in the back and move the older tire to the front. It is best to keep the rear tires the same and the front tires the same. So when replacing three, you want to make sure the two in the rear are the same tire, and that the new one up front is the same as the older tire that is currently on the vehicle. However, if there isn’t much tread life left on the one older tire, it would be best just to replace all four at that point.

When replacing four tires

At this point you have many different options. This is the best situation to be in because you can change the size and quality of your tires to suit your particular driving needs.

Q.How do I pick the right tire size?

You can determine the right size tire two different ways. You can search by your vehicle by entering in the year, make, and model in the vehicle and tire size search. Or you can determine your tire size by looking in your vehicle’s owner manual, on the inside of the vehicles door well, or analyzing the sidewall of your tire. Check out our tire size calculator to see the differences in speed and efficiency that changing your tire size will make. We also sort tires by vehicle so you can find the right tire for your car or truck in our vehicle tire area.

How to analyze the sidewall

Analyzing the sidewall can be tricky. But if you follow this guide, we will have you determining you tire size in no time!

Tire Size Guide

The P on the sidewall indicates it’s a passenger or performance tire. An “LT” indicates that it’s a light-truck tire.


Width is the distance between the outer edge and the inner edge of the tread of a tire.

Aspect Ratio

This determines how tall your tire is. The bigger the number, the taller the tire. Typically, higher performance tires have a lower aspect ratio. Most all-season passenger tires have a ratio between 65-80.


The "R" determines that it is a radial tire. Sometimes in higher performance tires it may have a VR or ZR. That just means it's a V or Z speed rated radial tire.


This is the diameter of the inner hole in the tire. This is basically the rim size this tire can fit on. Hence a 14 means it fits on a 14-inch rim.

Load Rating

Load rating refers to how much weight a tire can carry. A load rating of 82 indicates that a tire can support 1047 lbs. You will then multiply that number by four to determine the maximum carrying capacity of your tires. It is not a good idea to install tires with a lower load rating than what originally came on your vehicle. You can reference the chart below to find the amount of weight your tire can carry.

Load Index 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Load Lbs. 99 102 105 107 110 114 117 120 123 128 132 136 139 143 148
Load Index 16 17 18 19 20 21 22 23 24 25 26 27 28 28 30
Load Lbs. 152 157 161 165 171 176 182 187 193 204 209 215 220 227 234
Load Index 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Load Lbs. 240 247 254 260 267 276 282 291 300 309 320 331 342 353 364
Load Index 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Load Lbs. 375 386 397 408 419 430 441 454 467 481 494 507 520 536 551
Load Index 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
Load Lbs. 567 584 600 617 639 639 667 694 719 739 761 783 805 827 852
Load Index 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
Load Lbs. 882 908 937 963 992 1019 1047 1074 1102 1135 1168 1201 1235 1279 1323
Load Index 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
Load Lbs. 1356 1389 1433 1477 1521 1565 1609 1653 1709 1764 1819 1874 1929 1984 2039
Load Index 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
Load Lbs. 2094 2149 2205 2271 2337 2403 2469 2535 2601 2649 2756 2833 2910 2998 3086
Load Index 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
Load Lbs. 3297 3307 3417 3527 3638 3748 3858 3968 4079 4189 4299 4409 4541 4674 4806
Load Index 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
Load Lbs. 4938 5071 5201 5357 5512 5677 5842 6008 6173 6393 6614 6779 6844 7165 7385

Speed Rating

Each tire is issued a tire speed rating based on how well it reaches and sustains a certain speed. The higher the speed rating means the tire will provide better handling. It is best not to downgrade the speed rating of your tire and never mix different speed ratings on your vehicle. Both of these issues can lead to serious handling problems. Please reference the chart before to find your tire’s speed rating.

Speed Rating Test Speed (Not Recomended Speed)
Q Up to 100 MPH
S Up to 112 MPH
T Up to 118 MPH
U Up to 124 MPH
H Up to 130 MPH
V Up to 149 MPH
W Up to 168 MPH
Y Up to 186 MPH
Z 149 MPH and Higher
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Q.What tires best match my driving conditions?

After you have determined how many tires you need and your correct tire size it’s now time to figure out what kind of conditions you are most likely to encounter when you drive. Do you drive a lot in the rain or snow? Do you drive truck on-or-off roads? Do you mostly drive in dry weather? All of these conditions are factors when choosing the right tire for your needs.

What you want to do is analyze your driving conditions. You want to think of your worst possible driving conditions and balance them out with your typical driving conditions.

Worst possible driving conditions

If you use more than one set of tires and wheels; for example summer tires for summer and snow tires for the winter, you can select tires that will exactly meet your needs. However, if you use just one set for every season, you may get great performance under certain conditions but comprise on performance during other conditions. So it is important for you to match your tires based on the worst possible conditions you may expect to encounter.

Typical driving conditions

If most of your driving is around town, almost any tire will work for you. But, if you drive a lot on congested city streets or expressways during rush hour, you may want to get a tire that is more responsive and has better braking abilities. If you really only drive on interstates, than you will probably want a quiet, smooth-riding, long-wearing tire. If you drive on winding roads, you want to look for a better handling tire.

Balance the worst and the typical

If both conditions seem very similar, one set of tires is all you need. If you infrequently encounter snowy or hazardous conditions, you may want to select an all-season tire. If your worst conditions appear more frequently you may want to consider two sets of tires.

Types of Tires

What you want to do first, is indentify the kind of vehicle you are buying tires for. Or if you are in need of winter tires. Then you will want to choose a tire that best suits your needs.

Passenger Car/Minivan

These tires typically have taller sidewalls and emphasize benefits such as long-tread life, comfort, and dependability in a variety of weather conditions. Some of these tires are speed rated. Usually they range from S (up to 112mph) to T (up to 118mph). What you will want to do is compare the speed ratings to what is most important to your driving conditions. Remember the higher the speed rating, the better performance and handling a tire has.

Passenger tires are the most cost-effective tires available. They have all the main attributes one could look for in a tire; smooth ride, long wear, low noise, etc. However if you are looking for something a little better, but still not as pricey as a sport/luxury car tire, you can opt for a Touring Tire. These tires offer enhanced performance combined with excellent ride quality. They usually have a slightly lower profile and wider tread than an equivalent passenger tire, which helps the Touring Tire to handle and perform better at higher speeds.

Sport/Luxury Car

These tires are designed to provide confident handling and stability at higher speeds to maximize performance of sport/luxury cars where handling is very important. These tires are often used to enhance the look of just about any vehicle. They are available in lower profiles, larger wheel sizes, wider treads and stiffer sidewalls to improve cornering response and stability.

Tires in this category are most like classified as performance, high-performance and ultra high-performance tires. All these tires are speed rated. They typically range from H (up to 130mph) to Z (up to 149mph). Remember, ultra high-performance tires must be matched with ultra high-performance vehicle suspensions in order for you to appreciate the benefit of the tire. These tires are usually the priciest of all tires.


These tires usually have a higher load capacity than other tires. Load capacity is controlled by how much air is in the tire, and at what pressure. Tire sizes that begin with a “P” (Passenger) are meant to operate at lower pressures and loads than that of the same size that begins with “LT” (Light Truck). The “P” will have a better ride, but the “LT” will be able to haul a larger load.

The best way to decide which SUV/Truck tire you need is to figure out what you plan on driving on the most: on-highway, on/off highway (all-terrain) and off-highway (off road). On-highway tires have more of a rib tread design and off-highway tires have more of an aggressive blocky or chucky tread design. Make sure you pay attention to load index and speed rating when you choose the tire the best suits your needs.

All-Purpose (AP) Tires

These tires come factory installed on many of today’s vehicles due to their smooth highway ride and good all-season traction.

Sport Truck Tires

These tires offer sport car handling for trucks and SUVs, yet can handle the suspensions and load-carrying capacities of trucks. The all-season tread emphasize street handling and traction year-round.

All-Terrain Tires

This is a step up in off-road traction compared to all-purpose tires. Most drivers are willing to accept the worst performance on highways in order to get the additional traction.

Winter Tires

The days of studded winter tires seem to be over. So if you drive in wintery conditions, you will want a tire that can handle a wide range of winter conditions such as snow, ice, slush, rain to freezing rain, and of course dry highways. Winter tires utilize tread compounds that remain soft and pliable in the cold for reliable snow and ice traction without the need for studs. Please remember that winter tires should be purchased in sets of four.

So that about does it. We covered when you need to get new tires, how many tires to purchase, understanding tire sizes, and how to pick a tire for your specific driving conditions. Hopefully we made the process Simple enough for you.

You can find some more information about tires in the SimpleTire blog.

However, if you are ready, go ahead and buy yourself some sweet new tires!

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