TIRE INFORMATION

For the proper mounting of tires and wheels not purchased as a pre-mounted Tire & Wheel Package, be sure to observe some basic precautions:

Mounting and balancing should be done by a professional, using equipment designed for the job

• The wheel is not bent or damaged

• There is no buildup of dirt between the hub and the wheel

• All of the lugs have been properly torqued

• The wheel is securely seated on the hub

• The definition of balance is the uniform distribution of mass about an axis of rotation, where the center of gravity is in the same location as the center of rotation. In English, that would translate to …a balanced tire is when the mass of the tire, when mounted on its wheel and the car’s axle, is uniformly distributed around the axle. Even easier yet, how about… there are no heavy spots

Balanced tires can be the difference between a good or bad driving experience. Some cars (and drivers) are more sensitive to an out of balance tire than others, but no one is happy with a vibration.

An out of balance tire can adversely affect ride quality, shorten the life of your tires, bearings, shocks and other suspension components. If you have a vibration that is dependent on speed, and usually becomes noticeable around 40-45 mph and increases as your speed increases, it’s probably balance related. The other primary cause of vibrations is that the tire and wheel assembly isn’t perfectly round. Face it, if we go out far enough past the decimal point, nothing is perfectly round. This includes your wheels and tires. The problem is when the high spot on the tire, and the high spot on the wheel end up being matched to each other. This effectively doubles the amount of “hop” or runout. If re-balancing doesn’t cure the vibration problem, have your professional installer check the runout of the tire. If there is a “hop”, many times the problem can be fixed by simply rotating the tire on the wheel slightly. The technician should loosen the tire on the wheel, and turn it 180 degrees, and reinflate the tire after relubricating the bead. The runout should be significantly reduced or eliminated, and if it’s not, try it again, but this time rotate only 90 degrees, and if that doesn’t work, try 180 degrees on the third try. Done this way, the high spot on the tire has been tried at each quarter of the wheel. At one of those points, the tire should be good and round. At that point, rebalance the tire, and go for a test drive. If the vibration persists, the problem is either in the tire, or elsewhere in the vehicle.

REMEMBER!

Serious injury may result from explosion of the tire/rim assembly due to improper mounting – never exceed 40 psi (275 Kpa) to seat beads – mount only on designed diameter rims – only specially trained persons should mount tires.

To get the best wear and performance from your tires, the alignment of the tires is critical. Poor alignment occurs when the suspension and steering systems are out of adjustment. Incorrect alignment settings will usually result in abnormal treadwear. Take any unusual wear patterns as a clue, and get it checked, but before you do, make sure the inflation pressures are correct, as incorrect inflation can also cause uneven wear.

The different types of wheel alignments are front-end alignment, thrust angle alignment, and four wheel alignment. In a front-end alignment, the front only is checked. This is fine in some cases, but are the front tires properly positioned in front of the rear tires ? With the thrust angle alignment, that is checked so that the wheels are “squared” to each other. This would eliminate the “dog tracking” that you may have seen on a car that appears to be going down the road with rear end a foot over from the front. The best way to align the car is a four wheel alignment. This will not only do what the thrust angle alignment does, but also includes adjusting the settings on the rear of the car as well as the front.

Not all cars are fully adjustable, but some are. The measurements that need to be checked are caster, camber and toe.

Toe refers to the difference in distance between the front and the rear of the tires. If the distance between the tires is less in the front than it is in the rear, it is referred to as toe-in. It would be what could be commonly called “pigeon toed”. If the distance is greater between the front than it is in the rear, that would be toe-out.

Camber describes the amount the tire is tilted away from vertical. A tire has negative camber when the top of the tire leans inward toward the center of the vehicle. Positive camber is when the top of the tire is leaned outward from the center of the vehicle. The camber angle should be adjusted so that the tire is vertical under cornering load. Properly set camber will allow the tire to work at its best, but not have the tire putting too much of its force on the inner edge while moving in a straight line. Tire wear and handling become a compromise. Less negative camber typically will reduce the cornering ability, but give very even wear. Next time you see a photo of an Indy Car, see if you can notice how much camber there is. That is certainly an example of wear not being anywhere near as important as grip.

Caster is the most difficult of the three measurements to describe. If you think back to your bicycle and remember how the tire tilted slightly when turned, that was caster causing the tilt. If you drew an imaginary line through the upper and lower ball joints and compared the angle of difference to a line drawn perpendicular to the ground, the resulting difference is the caster angle. Caster settings allow the manufacturer to balance low speed steering effort and high speed stability. Increasing the amount of positive caster will increase low speed steering effort, but improve high speed stability. Caster also tends to cause an increase in the amount of negative camber as the steering angle is increased.

Regular wheel alignments will usually save you as much in tire wear as they cost. It should be considered routine, preventative maintenance.

Your tires support the weight of your vehicle, right? Well, they don’t! It’s the air pressure inside them that actually supports the weight. Maintaining sufficient air pressure is required if your tires are to provide all of the handling, traction and durability of which they are capable.

However, you can’t set tire pressure… and then forget about it! Tire pressure has to be checked periodically to assure that the influences of time, changes in ambient temperatures or that a small tread puncture has caused it to change.

The tire pressure recommended in your vehicle’s owner’s manual or tire information placard is the vehicle’s recommended “cold” tire inflation pressure. This means that it should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun’s radiant heat affects it.

Since air is a gas, it expands when heated and contracts when cooled. In most parts of North America, this makes fall and early winter months the most critical times to check inflation pressures… days are getting shorter… ambient temperatures are getting colder… and your tires’ inflation pressure is going down!

The rule of thumb is for every 10° Fahrenheit change in air temperature, your tire’s inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).

In most parts of North America, the difference between average summer and winter temperatures is about -50° Fahrenheit… which results in a potential “loss” of about 5 psi as winter’s temperatures set in. And a 5 psi “loss” is enough to sacrifice handling, traction, and durability!

Additionally, the difference between cold nighttime temperatures and hot daytime temperatures in most parts of the country is about 20° Fahrenheit. This means that after setting tire pressures first thing in the morning, the vehicle’s tire pressures will be almost 2 psi higher when measured in the afternoon (if the vehicle was parked in the shade). While that is expected, the problem is when you set your vehicle’s tire pressures in the heat of the day, their cold pressures will probably be 2 psi low the following morning.

And finally, if the vehicle is parked in the sun, the sun’s radiant heat will artificially and temporarily increase tire pressures.

We put some of these theories to the test at The Tire Rack. First, we mounted two tires on wheels. We let them sit overnight to equalize and stabilize their temperatures and pressures. The following morning we set them both to 35 psi. One tire and wheel was placed in the shade while the other was placed directly in the sun. We then monitored the ambient temperatures, tire temperatures and tire pressures through the day. As the day’s temperatures went from 67° to 85° Fahrenheit, the tire that was kept in the shade went from our starting pressure of 35 psi to a high of 36.5 psi. The tire that was placed in the sun and subject to the increase in ambient temperature plus the sun’s radiant heat went from our starting pressure of 35 psi to a high of 40 psi. In both cases, if we had set our tire pressures in the afternoon under the conditions of our evaluation, they would have been between 2 and 5 psi low the following morning.

Next we evaluated the effects of heat generated by the tire’s flexing during use. We tried to eliminate the variable conditions we might encounter on the road by conducting this test using our “competition tire heat cycling service” that rolls the tires under load against the machine’s rollers to simulate real world driving. We monitored the changes in tire pressure in 5-minute intervals. The test tires were inflated to 15 psi, 20 psi, 25 psi and 30 psi. Running them all under the same load, the air pressure in all of the tires went up about 1 psi during every 5 minutes of use for the first 20 minutes of operation. Then the air pressures stabilized, typically gaining no more than 1 psi of additional pressure during the next 20 minutes. This means that even a short drive to inflate your tires will result in tires that will probably be “underinflated” by a few psi the following morning.

Add all of these together, and you can understand why the conditions in which you set your vehicle’s tire pressures are almost as important as the fact that you do set it.

It’s important to remember that your vehicle’s recommended tire pressure is its “cold” tire inflation pressure. It should be checked in the morning before you drive more than a few miles, or rising ambient temperatures or sun’s radiant heat affects it.

And by the way, if you live in the North and park in an attached or heated garage you will “lose” pressure when you leave its warmth and venture into the real world outside during winter. Add 1 psi “cold” pressure tire pressure to compensate for each 10° Fahrenheit temperature difference between the temperature in the garage and outside.

Picture yourself driving along the highway, (just slightly over the limit, well, more than a little) and the sports news comes on the radio. The announcer mentions Shaquille O’Neal. Now, that guy has pretty big feet, but does he put more rubber on the ground with his Reeboks than your tires put on the road ? Hard to believe, but Shaq puts more rubber down than most cars do. The contact patch of most tires is about the size of your hand and has to handle a lot more weight and force than those big Reebok’s do.

The shape of a tire’s contact patch or “footprint” greatly influences its performance and is dependent on its profile or “aspect ratio”. Low profile tires (most performance tires) have a short and wide contact patch that is effective in converting the driver’s input into very responsive handling, cornering stability and traction… especially on dry roads.

High profile tires (light truck and most passenger tires) have a long and narrow contact patch which helps to provide predictable handling, a smooth ride and especially good traction in snow.

Plus sizing your wheels and tires is the best way to improve both the performance and appearance of your vehicle. By using a larger diameter wheel with a lower profile tire it’s possible to properly maintain the overall diameter of the tire, keeping odometer and speedometer changes negligible. By using a tire with a shorter sidewall, you gain quickness in steering response and better lateral stability. The visual appeal is obvious, most wheels look better than the sidewall of the tire, so the more wheel and less sidewall there is, the better it looks. Please contact our sales team for assistance in the proper sizing for your vehicle.

Tire rotation can be beneficial in several ways. When done at the recommended times, it can preserve balanced handling and traction of the tires and even out tire wear. It can even provide performance advantages. When should tires be rotated? We recommend that high performance tires be rotated every 3,000 to 5,000 miles, even if they don’t show signs of wear. Tire rotation can often be done with oil change intervals while the vehicle is off the ground anyway. Tire rotation helps even out tire wear by allowing each tire to serve in as many of the vehicle’s wheel positions as possible. Remember, tire rotation can’t correct wear problems due to worn mechanical parts or incorrect inflation pressures. It’s also important to check your owner’s manual for specific details on what method of tire rotation the vehicle’s manufacturer recommends.

While every vehicle is equipped with four tires, usually the tires on the front need to accomplish very different tasks than the rear tires. And the tasks encountered on a front wheel drive car are considerably different than those of a rear wheel drive car. Tire wear experienced on a performance vehicle will usually be more severe than those on a family sedan. Each wheel position can cause different wear rates and different type of tire wear.

While no one likes their tires to wear out, it is actually an advantage when all of the tires on a vehicle wear at the same rate throughout their life. As tire wear reduces tread depth, it allows the tires to respond to the driver’s input more quickly and increases dry road performance. Since tire rotation will help all of the vehicle’s tires wear at the same rate, it will keep the tires performing equally on all four corners.

When your tires wear out together you can get a new set of tires, without being forced to buy pairs. If you replace tires in sets you will maintain the original handling balance. And our suppliers are constantly introducing new tires, each of which improves upon their past product’s performance. If you replace your tires in sets, it allows you to experience today’s technology, instead of being forced to match yesterdays.

On front wheel drive cars, rotate the tires in a forward cross pattern (fig. A) or the alternative X pattern (fig. B)

On rear wheel or four wheel drive vehicles, rotate the tires in a rearward cross pattern (fig. C) or the alternative X pattern (fig. B)

If you car has directional wheels or tires, rotate them as shown in fig D.

If you car has non-directional tires that are a different size from front to rear, rotate them as shown in fig. E.

Molecules in air are so tiny they gradually work their way through the sidewalls of your tires and escape reducing air pressure even if the vehicle is parked.

It’s not 95 pounds of air, BUT 95 POUNDS PER SQUARE INCH OF AIR PRESSURE that’s doing the work.

Something unique about a tire is the fact that it is the only component on the vehicle which is not attached to the vehicle by bolts and nuts, screws or welding.

A tire remains attached to the vehicle ONLY due to the snug fit of the bead on the rim and the inflation pressure inside the tire, forcing the bead firmly against the bevel contour of the rim and rim flange.

If the tire loses its inflation pressure it will NOT remain attached to the vehicle.

BOOM!

Many drivers have under inflated tires!

Government Survey: Many Drivers Have Under inflated Tires by NEDRA PICKLER, Associated Press Writer, published August 29, 2001

WASHINGTON (AP) – Tens of millions of Americans will be hitting the road for Labor Day weekend, many unknowingly putting themselves in danger by driving with under inflated tires. The National Highway Traffic Safety Administration released a survey Wednesday that found about a third of all light trucks and a quarter of cars have at least one substantially under inflated tire.

Transportation Secretary Norman Y. Mineta urged drivers to check their tire pressure before making any holiday trips.

“Driving with substantially under inflated tires can lead to crashes and tragedy, in addition to reducing fuel efficiency and shortening tire life,” Mineta said.

NHTSA’s check of 11,530 vehicles around the country shows that despite government and industry warnings that under inflated tires can lead to deadly highway accidents, many people still are not keeping their tires inflated to recommended levels.

NHTSA recommends that tire pressure be checked once a month and before every long trip.

“People need to make it a regular part of their maintenance, not only to check the oil and the other fluids in the vehicle, but checking the tire pressure,” said NHTSA spokesman Rae Tyson.

The survey, conducted during two weeks in February, considered a tire under inflated if it was eight pounds per square inch or more below the vehicle manufacturer’s recommended inflation pressure. That’s 25 percent for a common recommended inflation pressure of 32 psi.

The survey found 27 percent of cars and 32 percent of vans, pickups and sport utility vehicles had at least one tire that was under inflated. Six percent of light trucks and 3 percent of cars checked had all four tires under inflated.

All vehicles made after November 2003 will be required to have a system to warn drivers about low tire pressure under a rule being drafted by NHTSA. The agency estimates the system will prevent dozens of deaths and thousands of injuries each year.

The Rubber Manufacturers Association has begun a multimillion-dollar campaign to encourage proper tire care called “Be tire Smart — Play your PART.”

PART stands for Pressure, Alignment, Rotation and Tread the key aspects of Tire Maintenance

Only 4 percent of respondents to a survey conducted for the association last year mentioned tire pressure checks when asked what routine tire maintenance is done on their vehicles. Fifty-five percent did not know where to find the correct pressure recommendation for their tires, which is in the owner’s manual and on the vehicle doorjamb.

“You made an investment in the tire, keep it running as long as you can,” said Donald Shea, president of the association. “And obviously, the safety is the most important part.”

Tires are comprised of many layers of rubber, steel and fabric. Due to these different components, your new tires require a “break-in” period to ensure that they deliver their normal ride quality and maximum performance. As tires are cured, a “release lubricant” is applied to prevent them from sticking in their mold. Some of the lubricant stays on the surface of your tires, reducing traction until it is worn away. Five hundred miles of easy acceleration, cornering and braking will allow the mold release lubricant to wear off, allowing the other tire components to begin working together. It is also important to note that your old tires probably had very little tread depth remaining when you felt it was time to replace them. As any autocrosser or racer who has tread rubber shaved off of his tires will tell you “low tread depth tires respond quicker.” Don’t be surprised if your new tires are a little slower to respond (even if you use the exact same tire as before). Their new, full depth brings with it a little more tread squirm until they wear down.

NOTE: Be careful whenever you explore the capabilities of your new tires. Remember that every tire requires a break-in period for optimum performance.

Since tires affect the personality and performance of your vehicle, all four tires should be as identical as possible or handling problems may arise. If your tires don’t match, it is possible that one end of your vehicle won’t respond as quickly or completely as the other, making it more difficult to control.

Consider the following:

JUST ONE TIRE?

If your tires have a lot of remaining tread depth, but you need to replace just one that has been damaged by an accident, road hazard or a vandal, you should replace it with a tire that exactly matches the others. Select a replacement tire of the same brand, line, size and speed rating. While there may be a less expensive tire available, it wouldn’t be a bargain this time because it would be different than the other three tires on your vehicle.

A PAIR OF TIRES?

If two of your tires have a lot of remaining tread depth, but you need to replace the other two because they were damaged or have worn out, you should replace them with a pair of tires that come as close as possible to matching your existing tires. While identical new tires are desirable, others of the same size and type can also provide good results. Only consider selecting new tires that are from the same tire category as your existing tires. New tires should be installed on the rear axle.

While your vehicle is being serviced ask your mechanic why one pair of tires have worn faster than the others. Was it caused by a lack of tire rotation, out-of-spec wheel alignment or loose mechanical parts? Once the problem has been found, it can be corrected before it damages your new tires. Keep in mind that your ultimate goal is that all of your tires always wear out at the same time so they can be replaced as a set.

A SET OF TIRES?

If all of your tires are wearing out together, you have the greatest flexibility in tire selection. If you were happy with the original tires, simply replace them. If you want longer tread wear, a smoother ride or more handling, there are probably tires that will help you accomplish that. Review the tire category types until you find a category description that describes a tire that fits your needs.

Buying the correct tire size can get complicated, especially if you decide to upgrade from your vehicle’s Original Equipment size.

A tire’s first requirement is that it must be able to carry the weight of your vehicle. No matter how good a tire you select, if its capabilities are “overworked” just carrying the load, it will have little reserve capacity to help your vehicle respond to quick emergency. So when you are in the selection process, make certain that your new tire’s size is designed to carry the weight of your vehicle! Don’t undersize.

The other size consideration is overall tire diameter. Since many of the functions of today’s vehicles are highly computerized, maintaining accurate speed data going into the computer assures accurate instructions coming out. And an important part of the speed equation is your tire’s overall tire diameter.

For cars and vans, staying within a ±3% diameter change is desirable. Pick-ups and sport utility vehicles (SUV’s) are usually engineered to handle up to a 15% oversize tire. Most tire dimensions can be calculated. For more information review the Tire Tech article, “Calculating Tire Dimensions.” While at first a ±3% diameter increase or reduction in tire diameter may sound very limiting, in most cases it allows approximately a ±3/4″ diameter change.

Additionally to help with the selection of substitute sizes, a system called “Plus Sizing” was developed. We use Plus Sizing to take into account the diameters of the available tires and the wheels, and then helps select the appropriate tire width that ensures adequate load capacity. Maintaining the tire’s overall diameter helps maintain accurate speed data going into the computer.

Ask yourself these questions to determine which performance category you should choose from:

Do you drive your car only in sunshine, or also through rain and snow? Do you drive your light truck on the road, off the road, or are you the one responsible for clearing the land to build the roads? To successfully meet each of these driving conditions requires a different type of tire.

WHAT IS THE WORST DRIVING CONDITION I WILL ENCOUNTER?

If you use more than one set of tires and wheels (for example, summer tires in summer and snow tires in winter), you can select tires that exactly meet your diverse needs. If you use one set of tires for every season, you may get good performance under many conditions, but you will compromise your vehicle’s performance when the conditions are at their worst.

So the important thing to do is to select your tires so that they match the worst driving condition you expect to encounter. When you’re stuck in the snow or in the mud because your tires don’t have the appropriate capabilities, you’ll curse their limited performance in your worst driving condition…and you’ll quickly forget how smooth and quiet they were at other times!

WHAT ARE THE TYPICAL DRIVING CONDITIONS I WILL ENCOUNTER?

If you only drive around your neighborhood and a “long trip” is one that’s just down to the corner convenience mart, almost any tire will do. But if you drive your vehicle on congested city streets and expressways during rush hour you will be better served by more responsive tires. If you drive extensively on the interstates you will want quiet, smooth riding, long wearing tires. Or if you like to drive quickly on twisting roads or through the mountains you will want good handling tires. And if you drive on the track or in autocross events, you will want the best competition tires available.

BALANCING THE REQUIREMENTS OF YOUR DRIVING CONDITIONS.

If your worst driving conditions and your typical conditions are similar, one set of tires will be all you need. If you live at the edge of the snow belt and infrequently get snow you may want to select an all-season tire. If your SUV is used as the family’s station wagon and driven on the road all of the time, overly aggressive light truck tires aren’t for you (unless you really like the “look”).

If your worst driving condition occurs frequently (you drive through snow all winter) and is dissimilar to your typical driving condition (you commute to work on the expressway during the week and spend your weekends at the beach), you may want to consider selecting two sets of tires for your vehicle. Each set will be designed to master the specific conditions without compromising your driving satisfaction at the extremes. While purchasing two sets of tires may appear expensive, the set you’re not using won’t wear while you are using the other set, and combined they’ll provide longer total wear than either set could individually!

Why is it that the price of fuel for our vehicle seems relatively inexpensive while the cost of its tires seems high? (Of course you already know that The Tire Rack tries to keep your tire costs as low as possible!) If we keep track of our total costs we will find that typical total fuel costs for just 10 to 20 thousand miles of driving actually exceed our tire costs. And believe us, we’ve found that the quality and performance of our tires has a lot more to do with our driving satisfaction than our fuel does.

We think that much of the misperception has to do with the fact that we buy fuel one tankful at a time, and don’t really look at its total cost for thousands of miles. Our tires are paid for “up front” and then last for tens of thousands of kms.

When you are selecting new tires and find one that is perfect, although more expensive than another tire that appears to be a close second; consider evaluating your situation by comparing “how much per mile” each tire will cost. If you plan to drive your vehicle another 30,000 miles and are considering the “perfect” tires at $100 each, and the other at $90 each; you may be surprised to find out that the cost of the “perfect” set costs just 1.3¢ per mile…while the close set costs 1.2¢ per mile. Will saving the $40 today make up for not having selected the “perfect” tire that you will be driving on for the next two years?

THE LAW

According to most states’ and provincial laws, tires are legally worn out when they have worn down to 2/32″ of remaining tread depth. To help warn drivers that their tires have reached that point, tires sold in North America are required to have molded indicators called “wear bars” across their tread pattern from their outside shoulder to inside shoulder. Wear bars are designed to visually connect the elements of the tire’s tread pattern and warn drivers when their tires no longer meet minimum tread depth requirements.

COMMON SENSE

However, as a tire wears it is important to realize that while its dry traction and handling will improve…its ability to perform in rain and snow will diminish. At 2/32″ of remaining tread depth, resistance to hydroplaning in the rain at highway speeds has been significantly reduced and traction in heavy snow has been virtually eliminated.

If rain and wet roads are a concern, you should consider replacing your tires when they reach approximately 4/32″ of remaining tread depth. Since water can’t be compressed, you need enough tread depth to allow it to escape through the tire’s grooves. If the water can’t escape fast enough your vehicle’s tires will be forced to hydroplane (actually float) on top of the water, loosing traction.

If snow covered roads are a concern, you should consider replacing your tires when they reach approximately 6/32″ of remaining tread depth to maintain good mobility. The reason that you need more tread depth in snow is because your tires need to compress the snow in their grooves and release it as they roll. If there isn’t enough tread depth, the “bites” of snow your tires can take on each revolution will be so small that your traction will be reduced. Because tread depth is an important element for snow traction, winter tires start with deeper tread depths than standard all-season or summer tires. Some winter tires even have a series of wear bars molded in their tread pattern indicating approximately 6/32″ remaining tread depth.

If you maintain your tires properly, they should provide you with mile after mile of trouble-free service. The answers to these FAQ’s will tell you what you need to know to get the most out of your tires. Pay special attention to the answers to questions about Inflation, Rotation, Balance and Alignment.

So many factors come into play, e.g. tread compounds, construction features, vehicle application, tire maintenance, geographic conditions, atmospheric conditions, driving habits, etc., it is not possible to provide a specific tire mileage expectancy. However, we do guarantee 60,000 kms/40,000 mi for each of our tires.

A vibration while driving indicates that your vehicle has a problem that needs attention. The tires, steering system and suspension system should be IMMEDIATELY checked to help determine the possible cause of the vibration. If the vibration is not corrected, it could cause excessive tire and suspension wear. It could even lead to a loss of control of the vehicle which could result in an accident.

Your tires may give you clear signs of wear problems in time to have them corrected before they cause permanent damage to the tires. You can prevent wear problems that shorten tire life by thousands of miles by learning to “read” the early warning signs and taking appropriate corrective action.

Here are some of the most common problems and their causes:

Saw tooth edges: CAUSE – MISALIGNMENT

The edges of the tread have a saw tooth or feathered appearance. This is caused by erratic scrubbing against the road. The solution is toe-in or toe-out alignment correction.

Cups or Dips in the tread: CAUSE – WORN PARTS

Cupping (also called dipping or scalloping) is most common on front tires, although rear tires can cup as well. It may be a sign that wheels are out of balance or that suspension or steering system parts need service or replacement.

Wear On Both Edges: CAUSE – UNDER INFLATION

If your tire looks like this, it may be under inflated. Not having enough air in a tire is singly the worst thing you can do to a tire. Under inflation reduces tread life through increased tread wear on the outside edges (or shoulders) of the tire. It also generates excessive heat which reduces tire durability and can lead to tire failure. Finally, it reduces fuel economy through increased rolling resistance (soft tires makes your vehicle work harder). Check your tires regularly for proper inflation. Abnormal tire wear may also be caused by misalignment or mechanical problems.

Wear in Center: CAUSE – OVERINFLATION

When a tire has too much air in it, the center of the tread bears most of the load and wears out faster than the outside edges. If a tire wears unevenly, its useful life is reduced. Check the inflation pressures of your tires at least once a month and before embarking on a long trip. Always check tires when they are cold, that is, before they have been driven on for one mile, or wait until one hour after they have been driven.

They certainly can. Here are some tips to increase the life of your tires:

• Don’t speed: excessive heat is generated when driving at high speeds. This heat increases the rate of tire wear and reduces the tire’s durability.

• Avoid fast turns on curves and around corners.

• Avoid fast starts and panic stops.

• Don’t ride on the edge of the pavement or drive over curbs, chuck-holes, or other obstructions.

Never choose a tire that is smaller in size or has less load carrying capacity than the tire that came with the car. Tires should always be replaced with the same size designation — or approved options — as recommended by the vehicle or tire manufacturer. The correct tire size can be found on the door placard of the vehicle or by consulting your local re-manufactured tire retailer.

Tires of different size designations, constructions, and stages of wear may affect vehicle handling and stability. For best all-around performance, the same type tire should be used on all four wheel positions. It is also recommended that you NOT mix radial and non-radial tires on a vehicle. However, if mixing tires is for some reason unavoidable, NEVER mix radial and non-radial tires on the same axle. If two radial and two non-radial tires are to be installed on a vehicle, the two radials MUST be installed on the rear axle and the two non-radials on the front axle.

When you buy a pair of replacement tires in the same size and construction as those on the vehicle, we recommend you put them on the rear axle. When you buy a single new tire, it should be paired on the rear axle with the tire having the greatest remaining tread depth. When radial tires are unavoidably used with bias or bias belted tires on the same car (not recommended), the radials must ALWAYS be placed on the rear axle. NEVER mix radial and bias-ply tires on the same axle.

Tire mounting is a job for tire professionals who have the proper training, equipment and experience. If you try to mount a tire yourself, you run the risk of serious injury to yourself and those around your, as well as possible damage to the tire and rim.

A tire that loses all or most of its air pressure must be removed from the wheel for a complete inspection to be sure it is not internally damaged. Driving for even short distances on under inflated tires may be dangerous and often damages the tires beyond repair. Most punctures, nail holes, or cuts up to 1/4 inch — confined to the tread — may be satisfactorily repaired by trained personnel using industry-approved procedures. An on-the-wheel plug-only repair is not reliable and may cause further damage to the tire. The proper repair of a radial tire includes the placing of a rubber patch on the inner liner of the tire. Do not attempt to have repaired tires with tread punctures larger than ¼ inch, or any sidewall puncture. Also, do not have repaired tires which are worn below 2/32nds inch tread depth. Make certain that your spare tire is always ready to go into service. Check it regularly for proper air pressure and be sure that it is in good condition. If your vehicle is equipped with one of the several types of temporary spares, be sure to check the spare tire’s sidewall for the correct inflation pressure, speed, and mileage limitations.

Many tires have tread wear indicator bars molded into the tread. When the tread is worn down to where you can see a solid bar of rubber across the width of the tread, it is time to replace the tire. If you don’t have tread wear indicator bars, you can measure the tread depth on your tires by placing a penny into a tread groove with the head upside down and facing you. If you can see the top of the head, it is time to replace your tires.

A bubble on the sidewall of a tire generally indicates damaged cords caused by severe impact. It is confirmed by a visible corresponding break in the inner liner. Air has infiltrated between the plies and caused the bulge. When a tire with damaged cords gets hot, it will experience a sudden loss of air. A tire with a bubble on the sidewall should be removed immediately. A tire in this damaged condition cannot be repaired.

You will find some degree of sidewall indentations on almost all radial tires. Indentations are formed where the fabric cord that is used in the body plies of the tire is lap-spliced together. These overlapping splices create slight indentations because the stretching capacity of the splices is less than the rest of the body ply material. In fact, the indentation is the most reinforced section of the tire. It is usually cosmetic and most times does not warrant concern. It is to be distinguished from a “bubble” on the sidewall which is far more pronounced and is perceived more as a lump than an indentation.

Each tire has a required Department of Transportation number imprinted on at least one of its sidewalls. That number begins with the letters “DOT” and may contain up to 12 additional numbers and letters. The first and the last digits are the most important for the tire owner. The first 2 letters/numbers identify the manufacturer of the tires. Prior the year 2000, the last 3 digits of a DOT number represented the week (2 digits) and the year (1 digit) of production. For example, if the last three digits are 439, the tire was produced in the 43rd week of 1999. Tires produced after January 1, 2000 have a 4 digit date code at the end of the DOT number. The first 2 digits represent the week of production and the last 2 digits represent the last 2 digits of the year of production. So, 3500 as the last 4 numbers indicates that the tire was produced in the 35th week of the year 2000.

Passenger and light truck tire warranties are generally for the life of the useable tread or for 6 years, whichever occurs first.