Tires Unlimited's Blog

Proper Tire Inflation

tiresunlimited — Tue, 12 Apr 2011 17:57:16 +0000

Maintaining proper air pressure is the single most important thing drivers can do for their tires. In the space of just one month, a tire can lose two pounds of air pressure.

It is important to check the air pressure of your tires regularly to make sure your tires are neither under- nor overinflated.

Underinflation is the worst enemy your tire can have. It causes increased treadwear on the outside edges (or shoulders) of the tire. It also generates excessive heat, which can reduce tire life. Finally, it reduces your fuel economy by increasing rolling resistance — soft tires make your vehicle work harder.

Overinflation is also detrimental to the tire. Too much air pressure causes the center of the tread to bear the majority of the car’s weight, which leads to faster deterioration and uneven wear. Any kind of uneven wear will shorten the lifespan of your tires.

To find the proper air pressure for your tires, look in the vehicle owner’s manual, on the sticker on the driver’s side doorjamb or in the glove box. If you buy new tires, be sure to learn the correct pressure from your tire Retailer or the owner’s manual of your vehicle. Check your pressure at least once a month, and use a high-quality air gauge.

Courtesy of www.goodyeartires.com

Balance and Aligment

tiresunlimited — Fri, 08 Apr 2011 05:18:10 +0000

Having your tires balanced and your vehicle properly aligned is important not only to the longevity of the tire but also to the safety of the driver and to the performance of the car.

Unbalanced tires cause road vibration, which can lead to driver fatigue, premature tire wear (also known as cupping or dipping) and unnecessary wear to your vehicle’s suspension. Tires should be balanced when they are mounted on wheels for the first time or when they are remounted after a repair. They should be rebalanced at the first sign of a vibration or shimmy and should be balanced at least once a year, regardless.

A vehicle is said to be properly aligned when all suspension and steering components are sound and when tire and wheel assemblies are running straight and true. Proper alignment is necessary for even treadwear and precise steering. Uneven front or rear tire wear, or changes in your vehicle’s handling or steering, can indicate misalignment.

The cost of keeping your tires balanced and your vehicle properly aligned will more than pay for itself in tire mileage, performance and comfort.

Courtesy of www.goodyeartires.com

Help To Improve Gas Mileage

tiresunlimited — Thu, 07 Apr 2011 05:17:48 +0000

Switch to fuel-efficient Assurance ^® Fuel Max^® tires. They can help you use less gas getting to your destinations.¹
Check your tire pressure at least once a month. Correct tire inflation pressure is critical for good fuel economy, tread life and vehicle performance.
Check your air filter for clogs. Replacing a clogged air filter can improve a vehicle’s gas mileage by as much as 10 percent.²
Using the grade of motor oil recommended by the vehicle manufacturer can improve gas mileage by 1 to 2 percent.³
Keep your vehicle properly tuned. Regular vehicle maintenance can improve gas mileage by an average of 4.1 percent.³

1. 2,600 miles based on a 4% fuel economy improvement, on 65,000 Mile Tread Life Limited Warranty, as compared to the standard Goodyear Assurance^® tire tested on P195/65R15 size – 2008 Honda Civic. Actual results may vary based on when tires are replaced, driving and road conditions, and proper tire maintenance.

2.(Source: Federal Trade Commission)

3.(Source: U.S. Department of Energy)

Help Your Tires Last Longer

Check your tire pressure monthly and before a long trip. Follow the manufacturer’s recommendations printed on the vehicle door placard or in the owner’s manual. It’s important to check the spare tire, too.
Inspect your tires once a month for uneven treadwear, cuts, cracks, bulges, foreign objects or other signs of wear or damage.
Have your tires rotated and the balance checked every 6,000 miles. Refer to your owner’s manual for complete details.

How To Save Money At The Gas Pump

Check Your Air Pressure
Keep your tires properly inflated and you could improve gas mileage by more than $1.50 every time you fill your tank. The recommended tire pressure for your vehicle is located on a sticker inside your driver-side door or noted in your owner’s manual.
Maintain Your Air Filter
Replacing a clogged air filter can increase your vehicle’s gas mileage by as much as 10%.
Watch The Weight
Excess weight in your vehicle can reduce gas mileage by 1-2% for every 100 pounds, so watch what you keep in your trunk.
Know Your Oil
Improve your gas mileage by up to 2% with the proper grade of motor oil.
Keep It Tuned
Keeping up with regular vehicle maintenance can allow you to increase your gas mileage by an average of 4.1%.
Keep It Capped
Did you know about 147 million gallons of gas evaporate every year from vehicles without gas caps?
Avoid Fast Starts
Don’t be a hot-head! Aggressive acceleration can reduce your gas mileage by up to a whopping 33%!

How Tire Pressure Gauges Work- Understanding Pressure

tiresunlimited — Wed, 30 Mar 2011 06:00:02 +0000

Let’s say you take a 1-inch by 1-inch piece of wood that’s 3 feet long, and let’s say this piece of wood weighs 1 pound. If you were to stand that piece of wood on-end on your foot, it would place 1 pound of force on your toe. Since its cross-section is 1 square inch, it exerts 1 pound per square inch of force (1 psi) on your toe. If you were to take a 30-foot-long piece of the same wood and balance it on your foot, it would apply 10 psi of pressure. If it were 300 feet long, it would apply 100 psi, and so on.

Water that is 1 foot deep exerts 0.43 psi, so if you are a mile underwater there’s about 2,270 psi being exerted. That is, a 1-inch-square column of water a mile high weighs 2,270 pounds.

Air works the same way. The atmosphere is about 50 miles “deep,” and at sea level it exerts 14.7 psi. That is, a 1-inch-square column of air 50 miles high weighs 14.7 pounds. Our bodies think 14.7 psi of air pressure is completely normal.

Courtesy of www.howstuffworks.com

5 Things to Look For in a New Tire- Price

tiresunlimited — Mon, 28 Mar 2011 23:56:44 +0000

As with all car-related purchases, price can be a factor in determining what type of tire you purchase and where you purchase it from. There are plenty of online options, but be sure to find out how much it costs to have your tires installed locally before you buy them online. Your local tire shop may not only charge you for mounting and balancing the tires, but may add in a few extra fees as well

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. If you do decide to buy online, ask around at local tire shops to find out which ones will agree to do the work and how much they’ll charge to put them on your car. If you choose buy tires from a brick-and-mortar store, keep in mind that not all tire shops carry the same brands and types of tires, so shop around until you’ve found the specific tire you’re looking for and the price you’re willing to pay.

For more information about tires and other related topics, follow the links on the next page.

by Christopher Neiger

Courtesy of www.howstuffworks.com

5 Things to Look For in a New Tire- Speed Rating

tiresunlimited — Thu, 24 Mar 2011 23:55:00 +0000

Yes, tires are rated by how fast they can go. Factory specifications will usually tell you what type of tire your car should have. There are performance tires available that are still able to perform in all-season conditions, so you don’t necessarily have to trade one for the other. These will have a rating on the side of the tire ranging from H to V and will provide better handling and a grip on the road, without the compromise of losing all-weather capability. High-performance tires on the other hand, sacrifice use in icy and snowy conditions, in order to provide the best in performance during wet and dry conditions. These tires will have a rating of V, W, Y, or Z. These tires are capable of sustaining speeds of 149 to 186 miles per hour (239.8 to 299.3 kilometers per hour), depending on the speed rating letter . Although high-performance tires will work well at lower speeds, too, keep in mind that the more performance-oriented a tire is, the shorter the expected tread life will be.

Coming up, we’ll take a look at one the most important factors when considering a new tire: the price.

by Christopher Neiger

5 Things to Look For in a New Tire- Size

tiresunlimited — Tue, 22 Mar 2011 23:51:26 +0000

This is an obvious one, but you really do need to know what the size of your factory tire is, and what size tire the wheel can take. Vehicle manufacturers design suspension and handling components with the factory wheel and tire size in mind. Changing the size of the tire can affect how your vehicle performs and handles . If you’re looking to add a larger size tire, take a look at your car’s owner’s manual first to see the manufacturer specifications and recommendations. If you’re making a drastic change in tire size, consult a tire expert before you do anything to find out how your vehicle may be affected. And remember: What looks good in the showroom may not be the best for your car’s on-road handling, suspension components or turning radius.

On the next page we’ll review speed ratings for tires.

by Christopher Neiger

5 Things to Look For in a New Tire- Longevity

tiresunlimited — Fri, 18 Mar 2011 23:43:08 +0000

When purchasing new tires, it’s important to know about how long you can expect them to last. Although tire manufacturers provide estimates on how many miles the tread is good for, tire longevity can be impacted by factors such as the elevation of the place they’re driven, how curvy the roads are and if they’re used in cold or hot climates. For all-season tires, the tread-life longevity is typically between 40,000 and 100,000 miles (64,374 and 160,934 kilometers) . High-performance all-season tires will only last from 40,000 to 70,000 miles (64,374 to 112,654 kilometers) and top-performance tires are sold without a guarantee on the tread life and usually don’t last more than 25,000 miles (40,234 kilometers) . When you’ve determined the types of features you’re looking for in a tire, consider how long you’d like the tires to last, and try factoring in if your commute could negatively impact the longevity of the tire tread.

On the next page, we’ll take a look at how size is an important part of the tire-buying process.

by Christopher Neiger

5 Things to Look For in a New Tire- Features

tiresunlimited — Wed, 16 Mar 2011 23:40:17 +0000

Tires, just like the cars that sit on them, can come fully loaded with features. Some tire manufacturers claim their tires can reduce the amount of stopping distance for your car, others aim to increase your car’s fuel economy and some can be used safely even after they’ve been severely punctured. But even if you’re just looking to replace your tires with another set matching the factory specifications, it’s good to know the types of features available.

Most drivers purchase the all-season tire, which may not increase your car’s miles per gallon, but will grip the road and perform well in most driving conditions, especially in dry weather . If you’re looking for something that can handle more extreme conditions, you can purchase tires for your vehicle that are designed for exceptional traction on wet roadways or on snow- and ice-covered roads. Snow tires sometimes have a severe weather icon on the sidewall, usually a mountain with a snowflake inside, and they offer even more traction than a typical all-season tire . Regardless of the tires you decide to purchase, do some research on which type of features you want in a tire and determine the features that work best for you and your specific driving needs.

Up next, how long should your new tires last?

by Christopher Neiger

Courtesy of www.howstuffworks.com

How Tires Support a Car

tiresunlimited — Mon, 14 Mar 2011 23:32:04 +0000

You may have wondered how a car tire with 30 pounds per square inch (psi) of pressure can support a car. This is an interesting question, and it is related to several other issues, such as how much force it takes to push a tire down the road and why tires get hot when you drive (and how this can lead to problems).

The next time you get in your car, take a close look at the tires. You will notice that they are not really round. There is a flat spot on the bottom where the tire meets the road. This flat spot is called thecontact patch, as illustrated here.

If you were looking up at a car through a glass road, you could measure the size of the contact patch. You could also make a pretty good estimate of the weight of your car, if you measured the area of the contact patches of each tire, added them together and then multiplied the sum by the tire pressure.

Since there is a certain amount of pressure per square inch in the tire, say 30 psi, then you need quite a few square inches of contact patch to carry the weight of the car. If you add more weight or decrease the pressure, then you need even more square inches of contact patch, so the flat spot gets bigger.

A properly inflated tire and an underinflated or overloaded tire

You can see that the underinflated/overloaded tire is less round than the properly inflated, properly loaded tire. When the tire is spinning, the contact patch must move around the tire to stay in contact with the road. At the spot where the tire meets the road, the rubber is bent out. It takes force to bend that tire, and the more it has to bend, the more force it takes. The tire is not perfectly elastic, so when it returns to its original shape, it does not return all of the force that it took to bend it. Some of that force is converted to heat in the tire by the friction and work of bending all of the rubber and steel in the tire. Since an underinflated or overloaded tire needs to bend more, it takes more force to push it down the road, so it generates more heat.

Tire manufacturers sometimes publish a coefficient of rolling friction (CRF) for their tires. You can use this number to calculate how much force it takes to push a tire down the road. The CRF has nothing to do with how much traction the tire has; it is used to calculate the amount of drag or rolling resistance caused by the tires. The CRF is just like any other coefficient of friction: The force required to overcome the friction is equal to the CRF multiplied by the weight on the tire. This table lists typical CRFs for several different types of wheels.

Tire Type	Coefficient of Rolling Friction
Low rolling resistance car tire	0.006 – 0.01
Ordinary car tire	0.015
Truck tire	0.006 – 0.01
Train wheel	0.001

Let’s figure out how much force a typical car might use to push its tires down the road. Let’s say our car weighs 4,000 pounds (1814.369 kg), and the tires have a CRF of 0.015. The force is equal to 4,000 x 0.015, which equals 60 pounds (27.215 kg). Now let’s figure out how much power that is. If you’ve read the HowStuffWorks article How Force, Torque, Power and Energy Work, you know that power is equal to force times speed. So the amount of power used by the tires depends on how fast the car is going. At 75 mph (120.7 kph), the tires are using 12 horsepower, and at 55 mph (88.513 kph) they use 8.8 horsepower. All of that power is turning into heat. Most of it goes into the tires, but some of it goes into the road (the road actually bends a little when the car drives over it).

From these calculations you can see that the three things that affect how much force it takes to push the tire down the road (and therefore how much heat builds up in the tires) are the weight on the tires, the speed you drive and the CRF (which increases if pressure is decreased).

If you drive on softer surfaces, such as sand, more of the heat goes into the ground, and less goes into the tires, but the CRF goes way up.

Courtesy of www.howstuffworks.com