Category Archives: Tire Information

Run Flat Tires – Things to Consider

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Dear Tracy,

I have heard that there is a new type of tire, called a run flat tire, that prevents blow outs. I recently had a blow out that scared me so badly, I almost wrecked. Can you tell me more about these tires? I really think I would like to get them!

Cindy W.

Dear Cindy,

You may have just heard about run flat tires, but they have actually been around for awhile. In fact, the idea for a self-supporting tire goes back to the 1930’s when a “bullet-proof” tire was developed for military vehicles and armored cars. This tire featured a sponge rubber inner tube that did not require air and was drivable, even after taking several bullets. (Tire history fans can read more in this 1935 article found in Popular Mechanics.)

Today’s run flat or zero pressure tires are designed to resist the unstable effects of deflation when punctured, and allow the vehicle to continue to be driven at a reduced speed for a limited distance, usually up to 100 miles. Run flat tires do not “prevent” blow outs, but they do keep your car more stable and drivable in the event of a flat. While these are good features, there are some draw backs to consider:

  • Run flat tires have much stiffer sidewalls so they are able to maintain vehicle weight. The result is compromised ride comfort.
  • The reinforcements necessary in run flat tires add weight to each tire. The heavier weight compromises vehicle handling.
  • Run flat tires may cost up to twice as much as standard tires. Some reports also suggest that they have a shorter life-span.
  • Drivers must pay close attention to tire pressure as pressure loss is harder to detect with run flat tires. While the use of a tire pressure monitoring systems (TPMS) can provide low pressure warnings, if those warnings are ignored, tire damage and destabilization may still occur.

Some vehicle manufacturers are designing vehicles to be equipped with run flat tires and engineering ways to offset these drawbacks. The good news is that as car manufacturers move in this direction, the technology behind the run flat design should continue to improve. One day, tires that prevent the type of experience you had may be the new standard.

Studded or Studless Winter Tires?

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Dear Tracy,

I have been hearing about studded tires and how they are best for driving on snow and ice. Is this just another name for winter tires or are they something all together different?

Jean A.

Dear Jean,

While studded tires are for winter driving, not all winter tires are studded tires. Studded tires feature a series of metal studs, which are built right into the tire tread. These studs are designed to penetrate snow and slush,  and grip into ice that lies beneath. Winter tires without studs, or studless tires feature a softer rubber than all season tires, which is intended to provide better gripping. The open tread design is another feature that gives winter tires better handling capability on slush and snow.

Like tire chains, the problem with studded tires is that if the studs are not digging into snow and ice, they are digging into the road surface. This is why studded tires are not allowed many areas. Typically if studded tires are permitted, it is only for specified times during the year. While studded tires do offer handling advantages such as better cornering ability, increased traction and more powerful braking force on snow and ice, they can actually cause a poorer handling on non-icy roads due to increased friction. Unless you are an ice road trucker, you are probably better off with studless winter tires.

Rolling Resistance & Fuel Economy

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Dear Tracy,

I know that I am going to need to replace my tires soon and am currently doing research on my options. Can you tell me how important a factor “rolling resistance” is when selecting tires? Is this a crucial feature in getting the best fuel economy with my car?

Adam S.

Dear Adam,

Rolling resistance refers to the force resisting motion when the tire moves along the surface of the road. The rolling resistance of a vehicle’s tires definitely does have an impact on its fuel economy. In fact, most vehicle manufacturers specify original equipment tires with low rolling resistance to optimize performance for government Corporate Average Fuel Economy (CAFE) mandate testing. These tires are usually designed for lower weight and rolling resistance, and can be constructed with thinner sidewalls and shallower tread depths. Even the tire’s chemistry may have an impact of rolling resistance. While good for fuel economy, these tires may not have all the attributes you would want in your replacement tires.

Fuel economy is one of many tire buying considerations you should think about in selecting a set of replacement tires. The type of tire you select should offer both performance and safety for your particular car, the type of driving you do, and for the climate in which you live and drive. Many of today’s major tire manufacturers are now offering fuel-saving, low-rolling-resistance tires. Make sure you work with your tire dealer to find a quality tire that offers a good balance of the features and benefits that are important to you.

Finally, when striving for the best fuel economy, remember that your tire selection is just the beginning. Proper tire maintenance is essential not only in getting the best fuel economy, but also making the most of your tire investment. Monitor your tire pressure at least monthly, and keep the pressure level at the amount recommended by the vehicle manufacturer. The correct pressure will be listed in your owner’s manual or labeled on the driver side doorjamb. Regular checks on balance and alignment will also help to make sure you get the best mileage and longest performance life from your tires.

Retired Tires

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Dear Tracy,

My dad recently made my little brothers a couple of tire swings from old tires, when he had to replace two tires on his truck. I think this is a great way to use old tires, but now I am wondering about other uses for old tires. Are there many ways to repurpose old tires, and keep them from going to landfills?

Rob R.

Dear Rob,

Concerns about the environment and good old fashioned creativity have lead to a lot of great ideas for how tires can be re-used. Below is a list of some of the ways that old tires can be beneficial after their primary useful life has expired:

Retreads: Old tires can be recycled into new tires. Called “retreads”, these tires are widely used on trucks and on airplanes.  Not all tires can be retreaded; they must be thoroughly inspected for damage, wear, and manufacturing defects. A large number of tires must be scrapped. In this case, the following uses are great options.

Energy from Tires: Almost half of all old scrap tires are used for energy. They are burned as fuel in factories and power plants. Cement kilns, paper mills and electric plants are examples of operations that use either whole or shredded scrap tires for energy. This keeps millions of tires from landfills and helps reduce the need for fossil fuels. Though burning tires releases gases and noxious substances, from an environmental standpoint, the output is cleaner than that of many other fuel sources.

Construction: Many states shred scrap tires and use the material in roads and other construction projects. This use for old tires is becoming more widespread. Scrap tire rubber is an inexpensive, lightweight product used to fill underneath roads where bogs, clay or other weak soils that cause construction complications. Scrap tires are also beneficial in sound walls, bridge foundations and even landfill development. Scrap tires can be shredded and used in liners, daily covers and other parts of the operation of a landfill.

Ground rubber: Instead of shredding scrap tires, sometimes tires are ground into tiny rubber pebbles for rubberized asphalt, or ground rubber mixed with conventional asphalt. Research shows rubberized asphalt lasts longer, creates lower road noise, and requires shorter stopping distances. Ground rubber is also used for patio decks, running tracks and the pliable black surface that is used in school playgrounds.

Nitrogen vs Air

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Dear Tracy,

Are there real advantages to inflating my tires with nitrogen instead of air? Is nitrogen that much different than air?

-Karl M.

Dear Karl,

Nitrogen is becoming more widely available as an alternative to air for inflating tires. While the air ordinarily used to fill tires is already 78% nitrogen, advocates say that filling with pure (93% to 95%) nitrogen does make a difference.

Nitrogen is said to be less sensitive to outside temperatures and better at maintaining tire pressure. Since nitrogen is supposed to maintain tire pressure better under hot and cold conditions, it can improve gas mileage, increase tire life, and is safer because tires are less likely to blow-out when driven at high speeds. Due to the fact that nitrogen is dry and does not support combustion, it has long been used in applications such as aircraft tires and racing tires, in which tires run extremely hot.

Another advantage said to be gained with nitrogen is that, as a dry gas, it reduces oxygen and moisture. This is important because oxidation accelerates as the tires heat up, causing damage to the tire and wheel. Air contains moisture, which increases oxidation and pressure fluctuation.

Some of the research available seems to suggest that while there are advantages to nitrogen use, the actual benefits tend to be modest.  Since you typically have to pay for nitrogen inflation, some drivers may not feel the benefits are worth the expense.

It is important to note that a big factor involved with the benefit of nitrogen is tire pressure. Checking and maintaining proper tire pressure will provide you with a host of benefits including longer tire life, improved safety, and better gas mileage, whether you fill with nitrogen or regular air.

What’s in a Tire?

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Dear Tracy,

I need to purchase new tires for my car, and I am trying to sift through all of the claims that the different manufacturers advertise. I think it would help if I had a better understanding of how tires are made, so I know what features are important.  Can you explain how tires are made in a way that is easy to understand?

-Jennifer J.

Dear Jennifer,

I think it is great that you want to be an educated tire buyer! Understanding the basic construction of tires is a great place to begin.

Tires are much more complex and technologically advanced today than ever before. Manufacturers combine engineering features and chemical formulas to create the best performing tires for a variety of road conditions, climates, and driving styles. The latest advances in tire technology offer the best in performance, ride comfort, fuel efficiency, safety, and reliability.

Tires are made up of many different elements, assembled in a tire building machine. The basic components of a tire include the bead, the body ply, the belt package, and the sidewall.

The bead, a loop of high-strength, rubber coated cable, is where the tire gets its strength. When tires are mounted on the wheel rim, the bead strength allows the tires to withstand the pressure of the mounting machine.

The body ply refers to the layers that make up the tire. Plies or layers of fabric are rubber coated, sealing and bonding the elements together. In addition to the bead, the strength of the tire also comes from the number of plies.

The belt package involves bands of steel incorporated into steel belted radial tires to reinforce the area under the tread. The belt package provides better road surface contact and puncture resistance.

The sidewall is the surface area, where you will find the identification letters and decorative features. The sidewall of the tire provides protection, stability, and resistance to abrasion.

After assembly, tires are cured and finished to precise specifications. It is during this step that all of the markings and tread patterns are molded into the tire. This is also when the heating or vulcanizing process bonds all of the components together in the final phase of creating the tire.