Nitrogen Infaltion -vs- Regular Oxygen Air Inflation?? Which One??

Filed Under: Service, Tires, maintenance by Scott
Jul.31, 2010

One of a tire’s primary tasks is to carry the weight of the vehicle. But anyone who’s ever had a flat tire knows that the tire doesn’t really carry the load…the inflation pressure inside it does! Using the correct inflation pressure not only provides the appropriate load capacity, it also enhances the tire’s performance, durability and contribution to vehicle fuel economy.

Tires are typically inflated with air that’s a combination of roughly 78% nitrogen (N2), 21% oxygen (O2) and 1% miscellaneous gases. And since all gasses expand when heated and contract when cooled, tire inflation pressures rise and fall with changes in temperature by about one psi (pound per square inch) for every 10° Fahrenheit change in temperature. This is one of the reasons it’s recommended that tire pressures be checked early in the morning before ambient temperatures, the sun’s radiant heat, or the heat generated by driving causes the tire pressure to rise.

And while tires appear solid, if you could see their microscopic structure you would find that rubber looks a bit like strands of cooked spaghetti stuck together. These molecular strands continuously stretch to and from their relaxed state every time the tire rolls and conspire to allow some of the gas to escape through the microscopic spaces between the rubber molecules (called permeation or diffusion). It’s been estimated that up to one psi of pressure may escape each month a tire is in service.

Fortunately compressed air is often available at gas stations, tire stores and auto repair shops. Sometimes it’s free, while other times it’s only available from coin-operated compressors. Unfortunately the compressed air often provided contains varying degrees of moisture depending on relative humidity and the compressor system’s ability to dry the air by removing moisture.

So what can we do to help maintain more constant tire pressures? We could change what we inflate our tires with.

Pure nitrogen has been used to inflate critical tire applications for years, primarily because it doesn’t support moisture or combustion. These include racing tires (IndyCar, Formula 1, NASCAR), aircraft tires (commercial and military) and heavy-duty equipment tires (earthmovers and mining equipment). The challenge facing nitrogen inflation hasn’t been its application; it’s been its method of supply and cost.

Nitrogen molecules have a more difficult time escaping through the microscopic spaces that exist between a tire’s rubber molecules. Nitrogen is a “slow” inactive gas labeled as an inert gas due to its nonreactive nature with many materials. Oxygen on the other hand is a “fast” active gas that reacts with many materials called “oxidation.” Additionally nitrogen is a dry gas that doesn’t support moisture while oxygen combined with hydrogen makes water (H2O).

What are the effects of using pure nitrogen to inflate tires?

  • Nitrogen is a gas and is still affected by changes in ambient temperature (about one psi for every 10° Fahrenheit). Nitrogen filled tires will require pressure be added during the fall/winter months as ambient temperatures and tire pressures drop. Nitrogen is good but can’t change the laws of physics.
  • Nitrogen reduces the loss of tire pressure due to permeation through rubber over time by about 1/3. This helps maintain the vehicle’s required tire pressures a little longer, but doesn’t eliminate the need for monthly tire pressure checks. This is good for people who don’t maintain their vehicles well.
  • Nitrogen is non-corrosive and will reduce oxidation and rust due to the absence of oxygen and moisture. This will help minimize wheel corrosion to promote better bead sealing. Tires that are used routinely will be replaced long before any life benefit would be received by using Nitrogen. This is most beneficial for drivers who drive their vehicles infrequently (car collectors, track drivers, snow tire users, motor home owners, etc).
  • Nitrogen is a dry gas and will not support moisture that could contribute to corrosion of the tire’s steel components (bead, sidewall reinforcement and belts) due to the absence of moisture over extended periods of time. However it’s important to remember that atmospheric pressure is constantly pushing oxygen and moisture into the rubber from the outside of the tire. This is especially good for low mileage drivers who don’t wear out their tires quickly or those that run average annual mileages but use long wearing radial (60K and 80K warranted) tires.
  • Nitrogen assures more consistent pressure increases due to increases in operating temperatures in a racing environment because of the absence of moisture. This is especially good for participants in track days, high-performance drivers education schools and road racing.
  • Drivers should use standard air if pressure adjustments are required when a local source of nitrogen can’t be found during a trip. While this reduces the benefit of higher nitrogen content, it is far better than running the tires underinflated in search of a source. Often the original nitrogen provider will refill the tires for free or a nominal cost when the driver returns to his hometown.

Several service equipment manufacturers have developed small, on-site nitrogen generator systems that use the selective permeation principle to separate oxygen and moisture from the shop’s compressed air lines to capture nitrogen. The key component is a membrane that separates the gasses. Each module contains hollow fibers that allow the oxygen and water vapor to be selectively removed, resulting in a source of nearly pure nitrogen that is kept in a separate storage tank until it is used to inflate tires.

The nitrogen generator, storage tank and filling system aren’t free and the dealer is entitled to some return on his investment. It’s time-consuming for a technician to bleed air from the tires (sometimes requiring several purges during the initial inflation) to achieve the desired nitrogen purity, however some of the latest equipment automatically goes through several purge cycles without requiring the technician’s participation.

While inflating tires with nitrogen never results in 100% purity, most nitrogen service equipment providers advise that reaching at least a 93% to 95% purity is necessary to receive the desired benefits. This ratio is normally achieved by initially purging the tires of existing air (down to just a few psi) and then refilling them with nitrogen. The purge/fill cycle is often repeated to achieve the desired level of nitrogen purity.

NOTE: Tires should never be subjected to a vacuum in an effort to eliminate the oxygen. Distorting the tire as shown in the accompanying picture can be as detrimental to the internal structure of the tire as running over potholes and road hazards.

So what should drivers do?

Overall, inflating tires with nitrogen won’t hurt them and may provide some minimal benefits.

Is it worth it? If you go someplace that provides free nitrogen with new tires, why not? Additionally we’ve seen some service providers offering reasonable prices of about $5 per tire (including periodic adjustments for the life of the tire) to a less reasonable $10 per tire (with additional costs for subsequent pressure adjustments) or more as part of a service contract, which we believe exceeds the value of nitrogen’s benefit.

Rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly.

Courtesy Tire Rack™

Tags: , ,
read more

Tire Pressure Monitoring Systems – What are they?

Filed Under: Tires, maintenance by Scott
Jun.17, 2010

Have you ever seen a vehicle with one or more tires that appear noticeably low on tire pressure? Didn’t you want to warn the driver of the situation before that slight inconvenience became a calamity? What if the vehicle with the low tire pressures is the one you’re driving? Wouldn’t you want to be warned?

The United States Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) has developed a Federal Motor Vehicle Safety Standard that requires the installation of tire pressure monitoring systems (TPMS) that warn the driver when a tire is significantly underinflated. The standard applies to passenger cars, trucks, multipurpose passenger vehicles and buses with a gross vehicle weight rating of 10,000 pounds or less, except those vehicles with dual wheels on an axle.

Maintaining the correct tire pressure for a vehicle is an important factor in how much load its tires can safely carry. The correct pressure will carry the weight without a problem. Too little tire pressure will eventually cause catastrophic tire failure.

Tires aren’t invincible. They are made of individual layers of fabric and steel encased in rubber. If a tire is allowed to run low on air pressure, the rubber is forced to stretch beyond the elastic limits of the fabric and steel reinforcing cords. When this happens, the bond between the various materials can weaken. If this is allowed to continue, it will eventually break the bonds between the various materials and cause the tire to fail. And even if the tire doesn’t fail immediately, once a tire is weakened it won’t heal after being reinflated to the proper pressure. So if a tire has been allowed to run nearly flat for a period of time, the tire should be replaced, not simply repaired or reinflated.

Studies have shown that running tires with too little air pressure is not uncommon. It’s been estimated that about one out of every four vehicles on the road is running on underinflated tires. This also means that one out of every four drivers is needlessly sacrificing their vehicle’s fuel economy and handling, and reducing their tires’ durability and tread life.

This has made tire pressure maintenance an important safety issue throughout the automotive industry and caused the U.S. government to pass legislation mandating tire pressure monitoring systems. The main purpose of these systems is to warn the driver if their tires are losing air pressure, leaving the tires underinflated and dangerous.

What types of systems are being used now? How do they work? Which works the best?

The National Highway Traffic Safety Administration (NHTSA) provides vehicle manufacturers options with which they can comply with the law. One option is to install a direct tire pressure monitoring system that uses pressure sensors located in each wheel to directly measure the pressure in each tire and warns drivers when the air pressure in any of their tires drops at least 25% below the recommended cold tire inflation pressure identified on the vehicle placard. Another option is to install an indirect tire pressure monitoring system that would warn the driver when a single tire has lost at least 25% of its inflation pressure compared to other tires on the vehicle. While direct systems could offer more precise warning thresholds, indirect systems cannot offer the same information or accuracy.

What’s the Difference?

DIRECT VS. INDIRECT

Direct Systems

attach a pressure sensor/transmitter to the vehicle’s wheel inside the tire’s air chamber. An in-car receiver warns the driver instantly if the pressure in any one tire falls below a pre-determined level.

Indirect Systems

use the vehicle’s antilock braking system’s wheel speed sensors to compare the rotational speed of one tire vs. the others. If one tire is low on pressure, it will roll at a different number of revolutions per mile than the other three tires, and alert the vehicle’s onboard computer.

Direct Monitoring Systems

Direct tire pressure monitoring systems measure, identify and warn the driver of low pressure. Because direct systems have a sensor in each wheel, they generate accurate warnings and can alert the driver instantly if the pressure in any one tire falls below a predetermined level due to rapid air loss caused by a puncture. In addition, direct tire pressure monitoring systems can detect gradual air loss over time. Some direct systems use dashboard displays that provide the ability to check current tire pressures from the driver’s seat.

Direct systems attach a pressure sensor/transmitter to the vehicle’s wheel inside the tire’s air chamber. Most Original Equipment and some aftermarket systems attach their air pressure sensor/transmitter to special tire valves. While the presence of a metal clamp-in valve typically identifies the presence of a direct tire pressure monitoring system, special snap-in rubber valves have also been used to support direct system sensors. The transmitter’s signal is broadcast to the in-car receiver and the information is displayed to the driver.

Some aftermarket and Original Equipment direct monitoring systems attach the sensor/transmitter to the wheel with an adjustable metal strap. These sensors/transmitters and their straps only weigh a few ounces and allow virtually universal application on car and light truck wheels. Since standard snap-in rubber valves are still used for these applications, it is important that the owners of these systems let their tire installer know that the vehicle is equipped with a direct system banded to the wheel before they change the tires.

Indirect Monitoring Systems

In the interest of providing a lower cost Original Equipment system, indirect tire pressure monitoring systems were developed by vehicle manufacturers wishing to comply with the law while minimizing development time and cost. Indirect systems use the vehicle’s antilock braking system’s wheel speed sensors to compare the rotational speed of one tire to that in another position on the vehicle. If one tire is low on pressure, its circumference changes enough to roll at a slightly different number of revolutions per mile than the other three tires. Reading the same signal used to support ABS systems, the vehicle manufacturers have programmed another function into the vehicle’s onboard computer to warn the driver when a single tire is running at a reduced inflation pressure compared to the others.

Unfortunately, indirect tire pressure monitoring systems have several shortcomings. Indirect systems won’t tell the drivers which tire is low on pressure, and won’t warn the driver if all four tires are losing pressure at the same rate (as occurs during the fall and winter months when ambient temperatures get colder). Additionally, our current experience with indirect systems indicates that they can generate frequent false warnings. We have found that false warnings may occur when the tires spin on wet, icy and snow-covered roads. In these cases, the false alarms would train the driver to disregard the tire pressure monitoring system’s warnings, negating its purpose completely.

read more

Price -vs- Value Things to Consider When Buying

Filed Under: Service, Tires, maintenance by Scott
Jun.03, 2010

How Do I Compare Price vs. Value?

While Courtesy Auto tries to keep tire costs as low as possible, price is often a consideration when purchasing tires. Even with high fuel costs, it seems less agonizing to fill the tank with fuel than invest in a set of new tires.

Why is it that the price of fuel seems relatively inexpensive while the cost of its tires may give the impression of being high? If we tracked our total costs we’ll find that typical fuel costs for just 10, 000 miles of driving for a car that delivers 20 mpg (see chart below) actually exceed our tire costs. And believe us, we’ve found that the quality and performance of tires has a lot more to do with driving satisfaction than fuel does.

We think that much of the misperception has to do with the fact that we buy fuel one tank-full 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 miles.

If you are selecting new tires to improve your car’s performance and come across two tires that have caught your eye, comparing their cost over the long run can help you decide. If one tire looks perfect, although more expensive than another tire that appears to be a close second, consider evaluating your options by comparing “how much per mile” each tire will cost.

Consider the following:

If you drive your sports car another 20,000 miles and are considering the “perfect” set of performance tires at $150 each, or another set that costs $130 each, you may be surprised to find out that the cost of the “perfect” set of four tires costs just 3 cents per mile…while the “second place” set of four costs 2.6 cents per mile. Will not spending the extra $80 today make up for not having selected the “perfect” tire that you will be driving on the next couple of years?

If you drive your vehicle another 60,000 miles and are considering “premium” long-wearing tires at $100 each, or economy tires costing $60 each, you may be surprised to find out that the cost of the “premium” set costs just 0.6 cents per mile…while the economy set costs 0.5 cents per mile. Will not spending the extra $100 today make up for not having selected the “premium” tire that you will be driving on the next four years? Will the economy tire last 60,000 miles?

If you live in the snowbelt and drive your vehicle another 60,000 miles and are considering 2 sets of tires (a set for summer and winter) at $100 each, or all-season tires costing $75 each, you may be surprised to find out that the cost of both “premium” sets costs just 1.3 cents per mile total…while the economy set costs 0.5 cents per mile. Will not spending the extra $500 today make up for not having selected the premium summer and winter tires that will make it easier to navigate snow and ice for the upcoming years?

Estimated Total Fuel Costs:
10,000 miles @ 15 mpg = 666 gal @ $3.37/gal = $2,244.00
10,000 miles @ 20 mpg = 500 gal @ $3.37/gal = $1,685.00
10,000 miles @ 25 mpg = 400 gal @ $3.37/gal = $1,348.00
10,000 miles @ 30 mpg = 333 gal @ $3.37/gal = $1,122.00

Courtesy Tire Rack
Tags: , , , , ,
read more

Automotive Aftermarket Industry Objects to Misleading Public Relations Initiative by AutoMD, a Division of US Auto Parts Network

Filed Under: Service, Tires, maintenance by Scott
May.26, 2010

Found this interesting being a member of ASA.  This is self serving and very inaccurate.

Courtesy ASA

BEDFORD, TEXAS, May 12, 2010 –The following is a joint statement by the Automotive Service Association (ASA) and Automotive Service Councils of California (ASCCA). The organizations are national and statewide membership organizations, respectively, of aftermarket service repair facilities and represent thousands of small business owners.

Recent public relations initiatives by AutoMD, a division of US Auto Parts Network, warrant a strong and clear response from the automotive repair and service industry. The company’s recent activities include a press release ranking U.S. cities according to the “honesty” of auto repair facilities in each city, as well as a television segment on the CBS Early Show. In both of these PR efforts the company makes several claims and promotes a set of conclusions that are inaccurate and based on flawed logic and biased methods.

We take particular issue with two of AutoMD’s efforts:

1) In a press release (Feb. 24, 2010), the company reported that it had “conducted a fairness check of over 600 shops in the top-50 DMAs” (including a range of dealers, independent shops, and franchises like Pep Boys)” to create a “Repair Shop Fairness Report” that ranked the “best and worst cities for auto repair.” A company that distributes auto parts knows better than anyone that parts quality and price varies substantially by brand, often 100% or more, and no mention of parts brand or quality was included in the survey. It also failed to account for differences in technician training, warranties included with the parts used, quality of equipment used and level of service provided by each type of facility. Furthermore, in each of the 50 cities included in their survey there are thousands of dealers, independent shops and chain stores. Their survey included an average of 12 shops per city, a number not anywhere close to what is needed to get an accurate or representative sample. Using biased methods allows US Auto Parts to reach whatever conclusions it desires.

2) In a segment on the CBS Early Show (April 14, 2010), the company brought its specially prepared vehicles to shops and dealerships in several states, asking for quotes on a front brake pad replacement at several shops. The CEO, Shane Evangelist, claimed the job should cost “about $180″ and stated emphatically that mechanics were ripping off consumers by charging more than $180. One mechanic that offered to do the job for $169 was widely praised for his honesty. Once again, no mention of parts quality, technician training or the quality of the equipment used in the facility was ever made, especially since quotes were being compared across multiple cities, each with different labor rates. More important, at no time during the broadcast was it revealed that AutoMD is owned by US Auto Parts, and according to its CEO during investor presentations, is using AutoMD as a lead generation platform for selling its parts. Taking the auto repair industry to task for its lack of transparency while failing to disclose its own self-serving motives is misleading.

Overall, US Auto Parts’ publicity campaigns are misleading to consumers and undermine our longstanding efforts to educate the motoring public and continually improve the professionalism of the industry. They perpetuate consumer mistrust of automotive professionals, devalue the development of expertise through ongoing training and education, ignore best practices and promote a race to the bottom. US Auto Parts’ attacks put repairers in a bad light and undermine the work of honest and reputable automotive service shops.

For further information, contact:

Ron Pyle, President
Automotive Service Association
PO Box 929
Bedford TX 76095
800.272.7467		 Jackie Miller, Executive Director
Automotive Service Councils of California
One Capitol Mall, Suite 320
Sacramento CA 95814
800.810.4272

About ASA
The Automotive Service Association is the largest not-for-profit trade association of its kind dedicated to and governed by independent automotive service and repair professionals. ASA serves an international membership base that includes numerous affiliate, state and chapter groups from both the mechanical and collision repair segments of the automotive service industry. ASA’s headquarters is in Bedford, Texas.

ASA advances professionalism and excellence in the automotive repair industry through education, representation and member services. For additional information about ASA, including past news releases, go to www.ASAshop.org, or visit ASA’s legislative Web site at www.TakingTheHill.com.

read more

Plus Sizing Tires and Wheels – How To’s

Filed Under: Tires by Scott
May.20, 2010

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.

- Scott

courtesy Tire Rack

read more

Inflation of Tires? What’s Too Much? Too Little?

Filed Under: Service, Tires, maintenance by Scott
May.10, 2010

Advantages of Correct Tire Inflation

Maintaining correct tire inflation pressure helps optimize tire performance and fuel economy. Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles. Tire deflection (the tread and sidewall flexing where the tread comes into contact with the road) will remain as originally designed and excessive sidewall flexing and tread squirm will be avoided. Heat buildup will be managed and rolling resistance will be appropriate. Proper tire inflation pressure also stabilizes the tire’s structure, blending the tire’s responsiveness, traction and handling.

When checking and adjusting tire inflation pressures, the “right” inflation pressures are those provided by the vehicle manufacturer, not the “maximum” inflation pressure branded on the tire’s sidewall. The vehicle manufacturer’s pressure recommendation can be found on the vehicle’s tire information placard label, as well as in the vehicle owner’s manual.

Which tire in the below pictures is Under Inflated?  It’s Hard to tell isn’t it?

This is what the tires may look like when sitting in your garage – Cant really see a difference in air pressure, can you?

Disadvantages of Underinflation

An underinflated tire can’t maintain its shape and becomes flatter than intended while in contact with the road. If a vehicle’s tires are underinflated by only 6 psi it could weaken the tire’s internal structure and eventually lead to tire failure. Lower inflation pressures will allow more deflection as the tire rolls. This will build up more internal heat, increase rolling resistance (causing a reduction in fuel economy of up to 5%) and reduce the tire’s tread life by as much as 25% while increasing the probability of irregular treadwear. Drivers would also find a noteworthy loss of steering precision and cornering stability. While 6 psi doesn’t seem excessively low, it typically represents about 20% of a passenger car tire’s recommended pressure.

Disadvantages of Overinflation

An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle’s tires are overinflated by 6 psi, they could be damaged more easily when encountering potholes or debris in the road, as well as experience irregular tread wear. Higher inflated tires cannot isolate road irregularities as well causing the vehicle to ride harsher and transmit more noise into its interior. However, higher inflation pressures reduce rolling resistance slightly and typically provide a slight improvement in steering response and cornering stability. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures.

Air is FREE at Courtesy Auto Service and Tire of Tacoma -Come by and well asses you tire condition and air pressure any time you may need it.

-Scott

read more

Understanding Treadlife/Mileage Warranties of Tires

Filed Under: Tires, maintenance by Scott
Apr.26, 2010

Tire treadlife/mileage warranties have become a popular marketing tool used by most tire manufacturers (and some independent retailers) to help position some of their tires competitively in the marketplace and to help indicate their potential longevity to consumers. Today they range from 30,000 miles to 90,000 miles. Unfortunately, due to the variety of road conditions and geographic influences encountered across the country, not all consumers will receive the warranted tire mileage. And while treadlife warranties seem straightforward enough, it is important to remember that they are a limited warranty and the consumer has to complete specific maintenance requirements to keep them in force.

The treadlife warranty only applies to the original owner and the original vehicle. Proof of purchase and vehicle mileage on the original installation date are required. The consumer is also required to prove that the tires were properly inflated, rotated and aligned, replacing worn suspension components as necessary.

The manufacturers correctly contend that if the tires have been rotated and properly maintained, all four tires will wear out evenly at approximately the same time. However, if the tire’s worn appearance indicates that they weren’t properly maintained, the tire manufacturer will not be obligated to honor the treadwear warranty.

Assuming that the tires have been properly maintained, let’s review how consumers receive their value. Our example will be a set of tires backed by a 5-year/40,000-mile treadlife/mileage warranty.

If a driver evenly wore all four tires down to 2/32″ of remaining tread depth in 30,000 miles, they would be offered a new set of equivalent tires from the same brand that would be discounted from their current retail price by 25% (prorating the value of 10,000 of the 40,000 miles of wear they didn’t receive). The driver would be required to pay the percentage difference between the warranted mileage and the mileage actually received as well as the cost of mounting, balancing and installing the replacement tires.

Treadlife/mileage warranties are also subject to time limits set by the tire manufacturers with most expiring 4-, 5- or 6-years from the date of purchase. This means that a 5,000 mile-a-year driver purchasing tires warranted for 5-years/40,000-miles would see it expire 5 years from the date of purchase even though they had only driven 25,000 miles. There would would be no warranty consideration due if those tires wore out after that.

One of the other problems consumers may have with any of the mileage warranties is that the tires must be worn down to the treadwear indicators before replacement under the warranty can be considered. That means that the tires must be at (or very near) the 2/32″ of remaining tread depth which is the minimum allowable legal tread depth for most states and has been adopted by the tire manufacturers as when tires are worn out. The difficulty is that since a tire’s hydroplaning resistance, wet traction and snow traction all diminish as it wears, the consumer may be faced with the dilemma of treadwear warranty vs. traction. If the winter or rainy season is approaching, the few dollars saved by running out the treadwear warranty probably won’t make up for the extra traction required by adverse weather conditions.

We’ll help you get the most mileage out of your tires at Courtesy Auto Service and Tire of Tacoma.

- Scott

Tags: , , , , ,
read more

Tire Maintenance – Protect your Investment and Safety

Filed Under: Tires, maintenance by Scott
Apr.17, 2010

When you do business with Courtesy Auto Service and Tire of Tacoma, we monitor whether or not it is time to rotate your tires, check air pressure and inspect your tires for their condition.  At a glance your tires might look good, but in many cases after lifting the car and getting a better look at the tire condition it reveals issues that either requires maintenance or replacement.  We will advise you properly and offer suggestions to make sure that you and your passengers are safe on the road.

With new tire purchases from Courtesy Auto Service and Tire of Tacoma your receive lifetime maintenance service on the tires which include; Free air checks, Free flat tire repairs, Free tire rotation and Free tire re-balancing.  We do everything in our power to make sure that your tires deliver many years of proper service and these services include a Nationwide Warranty offering peace of mind in your travels or service should you relocate.

Tire Rotation

The front tires on most vehicles tend to wear out faster than the rear tires. This is due to the effects of steering the vehicle and the weight transfer that occurs during braking. To ensure that all four tires wear evenly, it is important to rotate them on a regular basis. Tire rotation helps maintain balanced handling because it allows all four tires to wear at the same rate. Keep in mind, as tire wear reduces tread depth, it increases the tires’ response to driver inputs. Consequently, by equalizing tire wear at all four corners, dry road performance is actually enhanced. Another advantage of regular rotation is that it allows the tires to be replaced in complete sets rather than in pairs. This maintains handling continuity. It also enables drivers to take advantage of the latest in tire technology, instead of trying to match a pair of older tires.

Most manufacturers list rotation intervals in the scheduled maintenance section of the vehicle service manual and/or the owner’s manual. Tire rotation patterns can also be found in these books. If this information is unavailable for a particular vehicle, rotate the tires every 5-7,000 miles following the appropriate rotation sequence shown in the illustrations. After completing a tire rotation, be sure to reset inflation pressures to the manufacturer’s recommended specifications indicated on the vehicle tire placard.

To ensure that the proper amount of clamping force is applied to each fastener, follow these guidelines:

  • Make sure the area around the lug holes, as well as the wheel and hub mating surfaces are clean and dry. A wire brush can be used to remove corrosion and other debris. Wipe the areas clean using a shop rag.
  • Inspect the bolt holes for damage. Do not use a wheel if the bolt holes are deformed.
  • Inspect the wheel studs and lug nuts or lug bolts and bolt holes (depending on the vehicle) for damage. Replace or repair any damaged or worn components.
  • Always follow a star pattern when tightening lugs.

POPULAR TIRE ROTATION PATTERNS

(ONLY WHERE TIRES ARE THE SAME TYPE & SIZE)

Never rotate directional tires from side-to-side since this will reverse their direction of rotation. Directional tires can only be rotated from front to rear or vice versa. Directional tires are typically used on high-performance cars and can be identified by the arrows imprinted on the sidewall.

VEHICLES WITH DUAL REAR WHEELS

Some tires cannot be rotated in the manners described. Such tires include uni-directional tires and tires with asymmetric tread designs. Also, some vehicles may have different-sized tires mounted on the front and rear axles, and these different-sized tires also have rotation restrictions. Call the tire professionals at Courtesy Auto Service and Tire of Tacoma (253-473-5556) for proper recommendations for these specific cases.

-Scott

When you do business with Courtesy Auto Service and Tire of Tacoma, we monitor whether or not it is time to rotate your tires, check air pressure and inspect your tires for their condition. At a glance your tires might look good, but in many cases after lifting the car and getting a better look at the tire condition it reveals issues that either requires maintenance or replacement. We will advise you properly and offer suggestions to make sure that you and your passengers are safe on the road.

With new tire purchases from Courtesy Auto Service and Tire of Tacoma your receive lifetime maintenance service on the tires which include; Free air checks, Free flat tire repairs, Free tire rotation and Free tire re-balancing. We do everything in our power to make sure that your tires deliver many years of proper service and these services include a Nationwide Warranty offering peace of mind in your travels or service should you relocate.

Tire Rotation

The front tires on most vehicles tend to wear out faster than the rear tires. This is due to the effects of steering the vehicle and the weight transfer that occurs during braking. To ensure that all four tires wear evenly, it is important to rotate them on a regular basis. Tire rotation helps maintain balanced handling because it allows all four tires to wear at the same rate. Keep in mind, as tire wear reduces tread depth, it increases the tires’ response to driver inputs. Consequently, by equalizing tire wear at all four corners, dry road performance is actually enhanced. Another advantage of regular rotation is that it allows the tires to be replaced in complete sets rather than in pairs. This maintains handling continuity. It also enables drivers to take advantage of the latest in tire technology, instead of trying to match a pair of older tires.

Most manufacturers list rotation intervals in the scheduled maintenance section of the vehicle service manual and/or the owner’s manual. Tire rotation patterns can also be found in these books. If this information is unavailable for a particular vehicle, rotate the tires every 5-7,000 miles following the appropriate rotation sequence shown in the illustrations. After completing a tire rotation, be sure to reset inflation pressures to the manufacturer’s recommended specifications indicated on the vehicle tire placard.

To ensure that the proper amount of clamping force is applied to each fastener, follow these guidelines:

· Make sure the area around the lug holes, as well as the wheel and hub mating surfaces are clean and dry. A wire brush can be used to remove corrosion and other debris. Wipe the areas clean using a shop rag.

· Inspect the bolt holes for damage. Do not use a wheel if the bolt holes are deformed.

· Inspect the wheel studs and lug nuts or lug bolts and bolt holes (depending on the vehicle) for damage. Replace or repair any damaged or worn components.

· Always follow a star pattern when tightening lugs.

POPULAR TIRE ROTATION PATTERNS

(ONLY WHERE TIRES ARE THE SAME TYPE & SIZE)

Never rotate directional tires from side-to-side since this will reverse their direction of rotation. Directional tires can only be rotated from front to rear or vice versa. Directional tires are typically used on high-performance cars and can be identified by the arrows imprinted on the sidewall.

VEHICLES WITH DUAL REAR WHEELS

Some tires cannot be rotated in the manners described. Such tires include uni-directional tires and tires with asymmetric tread designs. Also, some vehicles may have different-sized tires mounted on the front and rear axles, and these different-sized tires also have rotation restrictions. Call the tire professionals at Courtesy Auto Service and Tire of Tacoma (253-473-5556) for proper recommendations for these specific cases.

Tags: , , , , , ,
read more

Tires, Tires, Tires – Unravelling the mysteries of what you need

Filed Under: Tires by Scott
Apr.16, 2010

Selecting the right tires for your vehicle is an important decision. Your safety, as well as driving enjoyment over the next years and thousands of miles will be determined by this decision. The information provided here and the advice/recommendations from the experts at Courtesy Auto Service and Tire will ensure you select tires that match your vehicle…and the way you drive it!

“How many tires do I need?”

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 treadwear, 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.

Once you know how many tires you will be replacing, determine size and type by answering the questions below:

What is the right size for my vehicle?

Buying the correct tire size can get complicated, especially if you decide to upgrade from your vehicle’s Original Equipment size. The expert sales team at Courtesy Auto Service and Tire is always ready to offer performance and fitment advice. Call 253-473-5556.

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 (SUVs) are usually engineered to handle up to a 15% oversize tire. Most tire dimensions can be calculated. 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.

Do I need summer tires, winter tires, all-season tires?

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.

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

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 snowbelt 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!

How do I compare price vs. value?

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 Courtesy Auto Service and Tire 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 miles.

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 cents per mile…while the close set costs 1.2 cents 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?

When should I replace my tires?

THE LAW

According to most states’ 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.

-Scott

Tags: , , , , ,
read more

Where do I install new tires? Break the Myth

Filed Under: Tires, maintenance by Scott
Apr.11, 2010

Most vehicles are equipped with the same size tire at every wheel position. Ideally all of these tires should also be of the same type and design, have the same tread depth and be inflated to the pressures specified by the vehicle placard or owner’s manual. This combination best retains the handling balance engineered into the vehicle by its manufacturer.

However due to a front-wheel drive vehicle’s front tires’ responsibility for transmitting acceleration, steering and most of the braking forces, it’s normal for them to wear faster than rear tires. Therefore if the tires aren’t rotated on a regular basis, tires will typically wear out in pairs rather than in sets. And if the tires aren’t rotated at all, it’s likely that the rear tires will still have about 1/2 of their original tread depth remaining when the front tires are completely worn out.

Intuition suggests that since the front tires wore out first and because there is still about half of the tread remaining on the rear tires, the new tires should be installed on the front axle. This will provide more wet and wintry traction; and by the time the front tires have worn out for the second time, the rear tires will be worn out, too. However in this case, intuition isn’t right…and following it can be downright dangerous.

When tires are replaced in pairs in situations like these, the new tires should always be installed on the rear axle and the partially worn tires moved to the front. The reason is because new tires on the rear axle help the driver more easily maintain control on wet roads since deeper treaded tires are better at resisting hydroplaning.

Hydroplaning occurs when the tire cannot process enough water through its tread design to maintain effective contact with the road. In moderate to heavy rain, water can pool up in road ruts, depressions and pockets adjacent to pavement expansion joints. At higher speeds, the standing water often found in these pools challenges a tire’s ability to resist hydroplaning.

Exactly when hydroplaning occurs is the result of a combination of elements including water depth, vehicle weight and speed, as well as tire size, air pressure, tread design and tread depth. A lightweight vehicle with wide, worn, underinflated tires in a heavy downpour will hydroplane at lower speeds than a heavyweight vehicle equipped with new, narrow, properly inflated tires in drizzling rain.

If the front tires have significantly less tread depth than the rear tires, the front tires will begin to hydroplane and lose traction on wet roads before the rear tires. While this will cause the vehicle to understeer (the vehicle wants to continue driving straight ahead), understeer is relatively easy to control because releasing the gas pedal will slow the vehicle and help the driver maintain control.

However, if the front tires have significantly more tread depth than the rear tires, the rear tires will begin to hydroplane and lose traction on wet roads before the fronts. This will cause the vehicle to oversteer (the vehicle will want to spin). Oversteer is far more difficult to control and in addition to the initial distress felt when the rear of the car starts sliding, quickly releasing the gas pedal in an attempt to slow down may actually make it more difficult for the driver to regain control, possibly causing a complete spinout.

Recommendations

Tires should be serviced periodically following the rotation patterns provided in the vehicle’s owner’s manual or as established by the industry to help enhance wear quality and equalize front-to-rear and side-to-side wear rates. The minor differences in tread depth between tires that might be encountered immediately after periodic tire rotations at 5,000-7,500 mile intervals won’t upset the vehicle’s hydroplaning balance and should not preclude rotating tires. For that matter, any differences in wear rates actually indicate that tire rotations should be done more frequently. Ideally tires should be replaced in complete sets. However when tires are replaced in pairs, the new pair of tires (assuming the vehicle is equipped with the same size tires all of the way around) should always be installed on the rear axle and the existing partially worn tires moved to the front axle.

While insufficient tire rotation intervals and/or out-of-adjustment wheel alignment angles often caused the differences in front-to-rear and side-to-side tire wear rates in the first place, the need to keep deeper treaded tires on the rear axle to resist oversteer conditions caused by wet road hydroplaning is important. Unfortunately this precludes the future possibility of ever rotating tires.

Once a pair of tires has been installed, the only way to escape being forced to drive on mismatched tires continually is to install a complete set of new tires (especially on front-wheel drive vehicles).

-Scott

Tags: , , , , , , , ,
read more