Ultimate Guide to Car Tires (Read Before Buying!)

Ultimate Guide to Car Tires

No part of your vehicle impacts your comfort and safety more than the tires. The right tires allow you to conquer slick roads, stop on a dime, and otherwise control your vehicle with ease. The wrong tires… well, the wrong tires pose serious dangers not just to yourself but also everyone else on the road.

Don’t let shopping for tires spin you in circles. Finding the best option is easy with our Ultimate Guide to Car Tires. It has everything you need to know, including tire types, maintenance tips, and more. We’ll even tell you what all those letters and numbers on the sidewall mean!

Ready to roll in safety and style? Let’s get started!

Types of Tires

Two major factors determine the type of tire you need:

  • Your vehicle
  • Where and how you drive

Here are the most common tire types:

All-Season

All-season tires are general-purpose tires suitable for small cars, light trucks and most small to midsize SUVs. They have year-round traction. The rubber used stays flexible in a wide range of temperatures, including extreme hot and cold.

On the downside, they lack precision handling and grip. Plus, they’re not particularly effective in the snow. Although fine for a light dusting, they generally don’t provide the traction needed for substantial driving through snow with an accumulation of an inch or more.

All-season tires break down into subcategories based on vehicle type:

All-Season Truck Tire

  • Designed for SUVs and Trucks
  • Best for holding heavy cargo
  • Estimated tread life between 40,000 to 80,000 miles
  • Typical wheel sizes between 15 to 22 inches

All-Season SUV Tires

  • Designed for SUVs
  • Suitable for everyday driving, light towing and occasional off-roading
  • Typical wheel sizes between 16 to 20 inches
  • Estimated tread life between 60,000 to 90,000 miles

All-Season Truck Tires

  • Designed for heaviest loads
  • Suitable for paved and unpaved roads
  • Provide additional traction for slippery conditions
  • Estimated tread life between 50,000 to 60,000 miles
  • Typical wheel sizes between 15 to 20 inches

Snow Tires

Snow tires provide traction and control when driving in snowy and icy conditions. Their unique construction features:

  • Tread blocks with large spaces
  • Treads with small cuts for traction (calling siping)
  • Soft rubber

They bite into ice and snow, allowing for reliable stopping and control in slippery conditions. Plus, the rubber stays pliable even in subzero temps.

However, snow tires aren’t for year-round use. Warm weather wears down the soft rubber, which results in a loss of traction and slower stopping. You’ll only want snow tires on your car during winter and the coldest parts of fall and spring. They’re not meant for use when the weather is consistently higher than 45 degrees.

Rubber or metal studs augment certain types of heavy-duty snow tires. While these extras do increase tread, they’re also illegal in many states. Check your local laws.

Performance Snow Tires

If you equip your car with high-performance tires during the summer months, you’ll probably want performance snow tires for winter. They provide the improved traction of traditional snow tires but with an increase in grip found in high-performance tires.

You won’t zip through the snow at high speed, but the improved grip can be substantial. Plus, driving with snow tires will feel similar to how your car handles in the summer.

Check out Snow Tires vs. All-Season Tires for more.

Performance Tires

Also known as summer tires, performance tires provide the best traction and grip. They’re wider with a lower profile than all-season tires. They’re available for just about any type of vehicle, but they’re especially popular on sports cars and other high-performance models.

Performance tires have superior traction, handling, and braking than all-season tires. They’re also available with the highest speed ratings, too. Most performance tires can handle speeds up to 149 mph.

However, they have downsides. Performance tires wear out much faster than the all-season type. Also, they’re far more susceptible to damage from potholes and other road-related problems.

Don’t drive a car with performance tires in cold weather. Traction is dangerously reduced. Plus, cold weather stiffens the tire’s thin rubber, resulting in damage.

However, performance tires typically work fine in wet conditions, just not cold and snowy ones.

Ultra-High Performance Tires

UHP tires provide the very best handling and steering. They’re often found on the fastest road racers. With a speed rating up to 189 mph, they’re the top-of-the-line tire type for high-performance autos.

However, they have more drawbacks, too. They’re not safe at all on icy and snowy roads. Plus, the tread wears down relatively quickly. You’ll likely need a new set of tires every season.

All-Terrain Tires

All-Terrain tires are a good choice if you mainly drive on paved roads but also enjoy occasional off-road adventures, too. They’re designed for trails, tracks, and other non-paved roads. You can drive on paved roads with all-terrain tires, too, but they do make a fair amount of noise compared to the other types.

Mud Tires

Mud tires are a special type of all-terrain tires made for hard-core adventuring. They’re made to tackle sand dunes, thick mud, rocks, and more.

However, they’re not suitable for everyday driving on paved roads. They have poor traction, wear down quickly, and make lots of noise. Only use mud tires for their intended purpose.

Light Truck Tires

Also called LT tires, Light Truck tires help support the heaviest loads. They’re frequently found in larger trucks, SUVs and commercial vehicles.

LT tires have a thick rubber which helps handle large weight even on uneven roads. They’re the best option if you frequently operate your vehicle at capacity or pull a trailer.

Are SUV Tires Different from Truck Tires?

You’ll find lots of tires labeled “SUV tires” and “truck tires.” Truthfully, they’re mainly marketing terms. Any tire can fit on an SUV or truck if it’s the right size.

However, Light Truck tires are an exception. They’re the best choice for commercial hauling.

Tire Code: The Meaning Behind Those Letters and Numbers

Printed on the side of the tire (the sidewall) is a line of numbers and letters. Although it looks weird, it’s packed with vital information.

From left to right, here’s what each part of the Tire Code means:

  • Tire Type
  • Tread Width
  • Aspect Ratio
  • Radial
  • Diameter
  • Load Rating
  • Speed Rating

Here’s a sample code for a common tire which we’ll use as an example: P215/60R15 87S

Tire Type

The tire type is either a one or two-letter code:

  • P – Passenger tires which fit most standard cars
  • LT – Light Truck tires help haul heavy loads
  • ST – Special Trailer tires haul large vertical loads
  • T – Temporary tires are spare tires

Passenger tires are the most common type. Almost all modern, non-commercial vehicles use Passenger tires. LT and ST are typically only used for vehicles which frequently haul large amounts of cargo. Finally, Temporary tires are used only as spares.

Size

The next four codes are Thread Width, Aspect Ratio, Radial, and Diameter. Together they’re commonly referred to as the tire’s size.

Tread Width

The next three numbers represent the cross-section width, which is the distance between the edges of the sidewall. It’s expressed in millimeters.

215 is the thread width from the sample.

Aspect Ratio

The Aspect Ratio is the two-digit number following the slash. It’s the ratio of the sidewall’s height to width. Our example width is 60%. The sidewall height is 126mm, which is 60% of the sidewall width (215mm).

Internal Construction

The Internal Construction tells you what the tire’s made from. You’ll see one of four options:

R stands for Radial. It’s a combination of steel and cords (mainly nylon) placed underneath the tread. They’re placed down in a radial pattern, which is a pattern of straight lines drawn from the center of a circle.

Radials are by far the most common type. They’ve been widely used for over 25 years.

B stands for Bias-Belt. It uses a belt made from steel or fiberglass to help prevent punctures under the tread. They provide a smoother ride.

D stands for Diagonal. It’s similar to the construction of Bias-Belt tires, except the cords are placed diagonally underneath the tread. They create a rough ride. Instead of D, these tires can also have a minus symbol (“-“).

Diameter

The next two numbers are the diameter of the wheel which will best fit the tire. Diameter is expressed in either centimeters and inches.

Load Index

The last two (sometimes three) digits indicate the total weight limit the tire holds. The load index is a number which corresponds to a weight. You’ll need to use a Load Rating Index. It’s a chart which converts the Load Index number to pounds.

The Load Index ranges from 60 to 139. A tire with a Load Index of 60 supports 550 pounds. A Load Index of 139 holds 5,357 pounds. Each Load Index represents the weight limit of one tire. You’ll need to multiply the pounds by four to determine the set’s total weight limit.

The Load Index is different than the vehicle’s payload limit. The payload limit is the total weight limit for your vehicle, including passengers, fuel, and cargo. Make sure the Load Index for the tires is more than the vehicle’s payload limit. Otherwise, they might not support your vehicle when it’s fully loaded.

Speed Rating

Finally, the last letter in the Tire Code represents the tire’s Speed Rating. It’s the safest maximum speed the tire can handle.

Tire rubber wears down with heat. Exceeding the recommended speed rating increases the risk of tire wear plus spontaneous tire failure. Here are the 12 tire ratings:

  • L – 75 mph
  • M – 81 mph
  • N – 87 mph
  • P – 93 mph
  • Q – 99 mph
  • R – 106 mph
  • S – 112 mph
  • T – 118 mph
  • U – 124 mph
  • H – 130 mph
  • V – 149 mph
  • W – 168 mph
  • Y – 186
  • Z – Open-ended

Speed ratings can be confusing because they’re not listed alphabetically. The most common ratings are T (118 mph), H (130 mph), and S (112 mph). T and H speeds are ideal for extended highway travel, especially in hot climates. S is the best option for driving around town.

Although the format described above applies to the vast majority of tires, some manufacturers may use slightly different systems. Always consult your owner’s manual for the specifics related to your vehicle.

The Tire Code isn’t the only information printed on the tire. You’ll also find the DOT code and the UTQG code. Here’s a closer look:

DOT Code

The DOT Code is easy to find because it starts with the word “DOT” followed by either a 10 or 13 digit string of letters and numbers.

DOT stands for “Department of Transportation.” The code is an official history of the tire’s creation. It consists of the following information:

  • Plant Code
  • Tire Size
  • Brand Characteristics
  • Manufacture Week
  • Manufacture Year

Plant Code

The first two (occasionally three) letters in the DOT Code represent the specific manufacturing plant which made the tire. Every tire manufacturer in the country must register with the federal government. Each plant code is stored in a database maintained by the Tire Safety Group.

Tire Size

The next two numbers represent tire size. However, it’s not the exact size of the size. To clarify, the Tire Size number in the DOT code represents a tire size category. Consumers don’t need to pay attention to the Tire Size in the DOT Code; it’s information mainly used by manufacturers.

Manufacturer Identity Number

The next three or four letters are the Manufacturer Identity Number. They’re used by the manufacturer to identify tires during recalls and similar nationwide events. Like the Tire Size above, customers don’t have any use for the Manufacturer Identity Number.

Date Code

The Date Code displays the tire’s date of manufacture. That’s right – it tells you the tire’s birthday!

The first pair of numbers signify the week. For example, the number 03 represents the third week of the year, which tells you the tire was made in January. The second pair of numbers indicates the year.

Pay attention to the tire’s age. Never use tires more than ten years old. Even if they’re barely used, they’re still susceptible to wear and failure. Most experts recommend swapping out tires after year six.

UTQG Code

The Uniform Tire Quality Grade is a federally-mandated code which lists three key characteristics about the tire. They’re required on all tires except spares, LT tires, and any tires with a diameter under 12 inches.

The UTQC codes display info related to the following:

  • Treadwear
  • Traction
  • Temperature Resistance

Treadwear

The first three digits refer to the typical pace which the tire will wear down. One hundred represents standard wear, while 200 represents tires which wear down twice as fast. Wear rate is estimated for properly maintained vehicles driven in ideal conditions. Harsh weather or a lack of maintenance will increase wear speed.

Traction

The next one or two letters indicate traction quality. From best to worst, traction ranks are:

  • AA
  • A
  • B
  • C

Traction is tested on wet asphalt and concrete.

Temperature Resistance

The final letter indicates the tires ability to dissipate heat at high speeds. It’ll be either A, B, or C. Tires with an “A” rating safely dissipate heat up to 115 mph. A “B” rating dissipates heat between 100 and 115 mph. Finally, a “C” rating dissipates heat between 85 and 100 mph.

How to Keep Your Tires in Safe Working Condition

Tires are stronger and last longer than ever before. They can last for 50,000 miles before showing signs of a problem. While this durability is a major benefit, it does have a minor drawback. Your tires might work so well that you’ll forget to perform routine maintenance.

Don’t forget to inspect your tires regularly. Small problems mean small, inexpensive repairs. However, small problems left untreated grow into major issues which can affect your safety on the road.

Tires wear down over time due to a combination of the following factors:

  • Heat
  • Cold
  • Road hazards (potholes, debris, etc.)
  • Underinflation

Check Air Pressure

Generally, you should follow the manufacturer’s recommendations regarding tire pressure levels. It’ll be listed in the owner’s manual as well on the inside of the driver’s side door. If you can’t find it on the door edge, check the glove box door and the gas tank cover.

The pressure listed on the sidewall is the tire’s maximum pressure limit. It’s different than the level recommended for daily driving.

Tire pressure is measured in pound-force per square inch. Most tires require around 30 psi, although some tires need as much as 100 psi.

Following the manufacturer’s recommendation is the best option for the most comfortable ride. However, it doesn’t always result in the best handling or most efficient gas mileage.

Many people fill their tires to 10% less than the maximum level (the number on the sidewall). That’ll usually give you better control over the car plus help you save at the pump.

You can inflate the tires closer to the max for long-distance driving and when carrying heavy cargo.

Check your tire pressure at least once a month. Ideally, you should check it after every fill-up. Check the pressure when the tires are cold; driving more than a few miles will affect the reading.

The pressure will likely differ in front and rear tires, so check them all. Also, check the pressure in your spare. It’s easy to forget about but should be ready to go if you ever get a flat.

Tires lose pressure every day. They lose about a pound or two during a month in cold weather, and even more in hot temperatures.

Check out the Best Tire Pressure Gauges for recommendations.

Check Treadwear

All tires wear down with time. However, how they wear down matters. The tire’s tread wear tells a story about your vehicle’s alignment and suspension. Ideally, tires wear down evenly. If certain sections have more wear than others, your vehicle likely has an issue.

Here’s how to interpret different types of wear:

Center wear – Overinflated tires.
Wear on both outer sections – Underinflated tires.
Wear on one side – Improper alignment

Limit Weight Capacity

Your vehicle’s payload capacity is the maximum amount of weight it can carry. It includes cargo, fuel, and passengers. You can find the payload capacity for your specific vehicle listed in the owner’s manual.

Never exceed your car’s payload capacity. Excess weight heats the tires, increasing wear, and risk of failure.

Inspect the Sidewall

Check the sidewall regularly. You’re looking for:

Cracks
Cuts
Bulges

Monitor Tread Depth

Tire tread requires a depth of 2/32 of an inch. Anything less reduces stopping power, traction and overall safety.

Tread inevitably wears down over time. Carefully monitor levels regularly to ensure you’re not driving around on bald tires.

All tires have what are called “wear bars.” They’re raised bars found on the bottom of the tread grooves. As the tread wears down, the bars become easier to see. When the wear bars are completely visible, it’s time to replace the tires.

The Lincoln Test

You can also test the tread depth using a method called The Lincoln Test. It’s easy, effective and only requires a penny.

Find the most worn section of the tire. Insert your penny into the tread. The top of Lincoln’s head goes into the tread (so Lincoln’s chin faces away from the tire).

Tread should cover Lincoln’s head. Only a small portion of his head, such as the top of his hair, needs coverage. If you can see all of Lincoln’s head and hair, your tire’s treads are too low.

Rotate Your Tires

Tires wear down differently depending on where they’re located on the car. Rotating your tires helps ensure even wear, which improves the tire’s lifespan and performance. Rotate your tires every 6,000 to 8,000 miles.

A mechanic can rotate your tires although it’s a fairly simple process many people feel comfortable doing at home.

Wheel Alignment and Balancing

Improper alignment increases the wear on your tires. It also impairs driving performance. Signs of an alignment problem include pulling, vibrations, wobbling, and bouncing. Realignment should be performed by a qualified mechanic because it typically requires special diagnostic equipment.

Tire Pressure Mounting System

Tire pressure significantly impacts fuel economy and vehicle safety. To help improve road safety and maintain clean environmental standards, Congress passed the TREAD Act in the year 2000. It mandates the installation of Tire Pressure Monitoring Systems in all vehicles made after 2006.

A Tire Pressure Monitoring System (TPMS) automatically monitors tire pressure and creates an alert when it’s low. There are two types:

  • Direct TPMS
  • Indirect TPMS

Direct TPMS uses wheel-mounted sensors to measure air pressure directly. When pressure drops below 25% of the manufacturer’s recommended level, an indicator light on the dashboard activates.

It’s the most accurate type of pressure monitoring. Sophisticated systems display the exact pressure level. However, on the downside, the sensors require batteries which need replacement, usually after about ten years.

Indirect TPMS connects to the wheel speed sensors in your car’s anti lock braking system. Low pressure slows a wheel’s rotation speed. The system detects the speed change and lights up the dashboard indicator. They don’t detect pressure directly, so they’re unable to provide detailed pressure readings.

All vehicles made after 2006 contain a Tire Pressure Monitoring System, as well as any vehicles which display a low-pressure warning on the dashboard.

While the TPMS is often reliable, you shouldn’t rely on it exclusively. Instead, check the tire pressure manually with a tire gauge. You’ll want to check your tire pressure at least once a month (although checking after every fuel fill-up is the best practice).

Popular Tire Manufacturers

Choose tires made from a manufacturer you trust. They should have an excellent reputation for quality. Plus, the tires should have a warranty against defects. Popular manufacturers include:

Bridgestone

Bridgestone is the third-largest tire manufacturer in the world. Headquartered in Tokyo, they also have a massive manufacturing plant in Nashville.

Aside from the Bridgestone brand, they also make Firestone, Dayton, and Fuzion tires. Popular throughout the United States, Bridgestone is an industry leader in snow tires.

Goodyear

Based in Akron, Ohio, Goodyear is the largest tire manufacturer in North America. Founded in 1898, they’re an American success story. They make tires under the brands Goodyear, Dunlop, and Kelly.

Michelin

Founded in France in 1891, Michelin has consistently remained at the forefront of tire technology. They even invented and refined the radial tire. Michelin tires are often an excellent option for all-weather use. Aside from Michelin, they also operate the BF Goodrich and Uniroyal brands.

Final Thoughts

Your car tires do more than get you from Point A to Point B. They have a dramatic impact on your car’s performance, fuel economy, and safety. Investing in the right tires improves every aspect of your driving experience.

Use the guide above to find the perfect tires today and enjoy all-new adventures behind the wheel!

Brett Gordon
 

The engine behind writing at DigMyRide.com and the brains behind its build. During the day, Brett is a thirty-something dude from SoCal climbing the corporate ladder, but by night, he spends most of his time contributing to the online world of cars, automotive tech & trends.

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