Air Pressure - Correct, Underinflated & Overinflated

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. 

Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles.

Can you easily identify which tire is 30% underinflated? Here is what they would look like in the morning parked in your garage.

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 lead to tire failure. Additionally, the tire's tread life could be reduced by as much as 25%. Lower inflation pressure will allow the tire to deflect (bend) more as it rolls. This will build up internal heat, increase rolling resistance and cause a reduction in fuel economy of up to 5%. You would experience a significant loss of steering precision and cornering stability. While 6 psi doesn't seem excessively low, remember, it usually represents about 20% of the 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 running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well, causing them to ride harsher. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures. The pressure must be checked with a quality air gauge as the inflation pressure cannot be accurately estimated through visual inspection.

Tire Contact Patch

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.

Wheel Lug Torquing

Proper installation requires torquing wheel-attaching hardware (lug nuts or bolts) to the recommended specification for the vehicle make, model and year. Torque specifications can be found in the vehicle's owner's manual, shop repair manual, industry reference guides or obtained from the vehicle dealer.

 Proper torquing requires using the correct tools, procedures and patterns to prevent over-tightening hardware, stripping threads and stretching studs, as well as will reduce the possibility of warping brake drums, brake rotors or suspension hubs. 

Under- or over-tightening wheel-attaching hardware can be damaging and dangerous. 

Torque specifications are for threads free of dirt, grit, corrosion, etc., so the hardware turns freely. While lubricating hardware THREADS is recommended, it is important NOT to lubricate hardware SEATS. The friction which torque is measured against should come from the hardware seats. Lubricating hardware seats can result in inaccurate torque readings and/or over-torquing the hardware.

Professional  recommends starting hardware by hand, snugging them manually and then using a beam or click-type torque wrench to apply the final torque and confirm the recommended torque value has been reached. 

Professional does not recommend using impact guns or torque sticks when installing wheels.

Impact guns deliver torque as torsional impacts, made by internal hammers. Delivering torque as torsional impacts can damage hardware and wheel finish. Some vehicles, such as Porsches, require the use of special sockets to tighten the hardware without damaging their anodized coating. 

Torque sticks are designed to limit applied torque by absorbing input torque thru torsion deflection, or twist. However, there are many variables that can affect the torsional deflection (absorbed torque) and the applied (delivered) torque. These can lead to inaccurately applied torque or variations in applied torque.

Some of the variables that can cause inaccurate torque delivery: 

Type of impact used (air, electric, cordless) 
Power (air pressure, air volume, length of hose, size of fittings, battery power, battery age) 
Impacts per second 
Size of internal hammers 
Possible use of additional adapters 
Socket size, weight, length 
Operator grip strength 
Weight of the impact
 Applied angle during use

Attempting to fully tighten hardware with impact guns/torque sticks also prevents using a click-type torque wrench to confirm the specified amount of torque is present. While a click-type torque wrench can identify when the selected torque has been reached, it cannot diagnose excessive torque. 

Once you have the right tools, use the appropriate crisscross sequence (patterns shown below) for the number of the vehicle's wheel-attaching hardware positions until all have reached their specified torque value.

New wheels should be re-torqued after the first 50 to 100 driving miles. 

This should be done in case the clamping loads have changed following the initial installation due to the metal compression/elongation or thermal stresses affecting the wheels as they are breaking in, as well as to verify the accuracy of the original installation. 

When rechecking torque value, wait for the wheels to cool to ambient temperature (never torque a hot wheel). Loosen and retighten to value, in sequence using the torque procedures listed above.

Tire Sidewall Separations / Bubbles

Pneumatic tires are made of specialized rubber compounds reinforced by plies of fabric cords and metal wires. While most rubber compounds can be stretched easily, the underlying fabric cords and steel wires actually define the tire's shape by limiting stretching. In order to bond these dissimilar materials, the cords and wires are coated with adhesives and/or rubber before the other components are bonded to them during curing. 

A strong bond between these various components is necessary to provide the desired durability. However the strength of the bond can be reduced if 1) any of the components are contaminated during manufacturing (resulting in incomplete bonding), or 2) components are damaged in service due to use while overloaded/underinflated, or by impact with potholes, curbs or other road hazards that pinch the tire between the rim and the road, or simply stretch the rubber beyond the elastic limit of the underlying cords and wires.

Sidewall Undulation Past experience indicates that a sidewall separation/bubble caused by component contamination or incomplete bonding during manufacturing will appear within the first six months of service. Fortunately these separations/bubbles typically appear when they are small in size and before the tire's strength is substantially reduced. However since typical tires roll about 800 times every mile and the air pressure inside the tire is greater than outside, tire separations/bubbles that are unseen or ignored will continue to grow in size, further reduce strength, often generate noise and vibration, and ultimately lead to tire failure as the tire stretches under load (similar to the way that continuously bending a paperclip back and forth will cause it to weaken and break). However there is one last thing to remember; while a separation/bubble early in a tire's life is usually associated with a manufacturing condition, even a single, significant impact with a deep pothole or sharp curb can cause a new tire and wheel to be damaged. 

If the sidewall separation/bubble appears after six months of on-vehicle service, prolonged driving on overloaded/underinflated tires or a road hazard are the most likely causes. However it may take weeks or months after an impact for a separation/bubble to appear as the damaged or bruised area continues to weaken. Unfortunately the time differential between the impact that caused the initial damage and the delayed appearance of visible evidence often means that the driver has forgotten about the impact that damaged the tire in the first place. 

The varieties of possible causes make it necessary to inspect the tire while mounted on the wheel (sometimes the wheel will show impact damage adjacent to the separation/bubble), as well as to dismount the tire and inspect the condition of its innerliner thoroughly. Sometimes it is necessary to return a tire to the manufacturer's inspection center where it can be dissected before the actual cause can be determined. 

While taller profile tires can be damaged by the more severe impacts with deeper potholes and sharper curbs, low profile tires mounted on large diameter wheels are the most susceptible to this type of damage. The driver of vehicles equipped with low profile tires should make special efforts to avoid potholes, curbs or other road hazards.

Tire Rubber Cracking

Tires are subjected to one of the harshest environments experienced by any consumer product. In addition to being stretched millions of times as they roll through their life, tires are exposed to acid rain, brake dust, harsh chemicals and direct sunlight, as well as summer's heat and winter's cold. And while a tire's rubber compounds have anti-aging chemicals in their recipes, exposure to the elements will eventually cause rubber to lose some of its elasticity and allow surface cracks to appear. 

"The anti-aging chemicals used in the rubber compounds are more effective when the tire is exercised...The repeated stretching of the rubber compound actually helps deter cracks from forming."

The surface cracks that occasionally appear have been called many things: Weather Checking, Weather Cracking or Ozone Cracking. These small cracks typically develop in the sidewalls or at the base of the tread grooves. Depending on their severity, they may be cosmetic in nature if they don't extend past the rubber's outer surface, or may be a reason to replace the tire if they reach deep into the rubber.

 Because all tires are made of rubber, all tires will eventually exhibit some type of cracking condition, usually late in their life. However, this cracking can be accelerated by too much exposure to heat, vehicle exhaust, ozone and sunlight, as well as electric generators and motors (that have armature brushes). For example, a vehicle parked outside instead of in a garage will constantly expose its tires to the rays of the sun, increasing the likelihood of cracking. Additionally, some sidewall cracking has been linked to abrasion from parking against a curb, or the excessive use of tire cleaners/dressings that inadvertently remove some of the tire's anti-oxidants and anti-ozone protection during every cleaning procedure. Interestingly enough, when sun exposure or excessive cleaning is the cause of the small cracks, the sidewall of the tire facing outward will show damage, while the sidewall facing inward is rarely affected.

 The anti-aging chemicals used in the rubber compounds are more effective when the tire is "exercised" on a frequent basis. The repeated stretching of the rubber compound actually helps resist cracks forming. The tires used on vehicles that are driven infrequently, or accumulate low annual mileage are more likely to experience cracking because long periods of parking or storage interrupt "working" the rubber. In addition to being an annoyance to show car owners, this condition often frustrates motor home and recreational vehicle owners who only take occasional trips and cannot even park their vehicle in a garage or shaded area. Using tire covers at least minimizes direct exposure to sunlight. 

Tire manufacturers' warranties typically cover cracking for a period of 4 years from the date the tire was purchased (receipt for the new tires or in-service date of the vehicle required) or four years from the date the tire was manufactured. 

There are a few conditions that would possibly void the manufacture's coverage. The same types of cracks can also be caused by poor tire maintenance practices. Driving on a tire that was flat, or one that was underinflated or overloaded causes excessive stretching of the rubber compound, and may result in cracks that appear similar to the surface cracks mentioned above. The manufacturers' warranty might not apply if an interior inspection of the tire clearly indicates that the cracks were due to these conditions.

Tire Wheels Finishes & Care

Once your new wheels and tires are installed, step back and take a good look. The new, sharper appearance will accent your vehicle splendidly. They look great now; but unfortunately, your wheels are often the dirtiest part of your car because they are constantly exposed to the elements (corrosive brake dust, ocean or road salt, stones, cinders and sticky tar). 

Cleaning Wheels Damage caused by prolonged exposure to these elements will void the finish warranty on your wheels. It's important to clean them properly and often. 

Here are a few tips on how to maintain a wheel's original splendor.

 Before you install them, a coat of wax will help protect your wheels and make them easier to clean.

 Treat the finish of your wheels as you would the finish of your car. Most alloy wheels today feature a painted and/or a clearcoat finish. The best way to take care of wheels without damaging their protective finish is by frequently washing them with a mild soap and water solution. Using a tar and bug remover can prevent permanent tar staining. Periodic waxing will protect the wheel's finish from the elements. 

Never use abrasive cleansers, steel wool pads or polishing compounds.

 Beware of automatic car washes. Some washes use acid cleaners either before or during the wash to remove dirt and grime. Others use stiff brushes for cleaning wheels and tires. Both of these processes could harm your wheel's finish. Wheels with low profile tires can be damaged by the metal tracks used in most car washes. Ask the employees of the car wash about their equipment and procedures before entering the wash. 

Never allow your wheels and tires to be steam cleaned. Steam can dull the paint and clearcoat finish on your wheels.

 Don't clean hot wheels — wait until they cool. Cleaning wheels while they are hot may cause your mild soap solution to dry too quickly leaving spots or a film of soap on your wheels. 

Clean your tires and wheels first, one at a time. Tires and wheels tend to be the dirtiest parts of your vehicle and have a variety of surfaces to clean. So you will want to use the full strength of your hose to initially rinse away all loose dirt and to finally rinse off your soap solution. If you clean your tires and wheels first, you won't expose your washed car to the over spray as you rinse them. Cleaning one at a time focuses your attention and ensures that the soap doesn't dry on one wheel while you're cleaning another. Be sure to use a different sponge on the rest of the car's body to prevent scratching the paint from the particles that may have collected during the wheel cleaning process. 

Clean wheels on a regular basis. Your new tires and alloy wheels are like any other valuable investment. Care for them as you would care for your entire vehicle.

Flat Tire Repairs - After Driving on Flat Run-Flat Tire

Most run-flat tires make a promise of temporary extended mobility at up to 50 miles per hour speeds for up to 50-mile distances in the event a puncture allows complete air pressure loss. However, even if driven within their speed and distance limitations, driving on run-flat tires with low or no air pressure can permanently damage their internal structure, surrendering strength and durability. 

Therefore, Tire Rack recommends driving the slowest safe speed below 50 miles per hour and the shortest distance to a service provider's facility.

 Unfortunately, when it's time to consider repair, even a trained tire specialist may be unable to confirm internal structure damage resulting from a run-flat tire having been driven in a severely underinflated or zero pressure condition. Such damage may not be visible on the surfaces of the tire's exterior sidewalls or interior liner making it impossible to determine tire suitability for repair or reuse. Because of this, Tire Rack and many tire manufacturers recommend replacement of run-flat tires driven in a severely underinflated or zero pressure condition. 

Rubber Manufacturer Association (RMA) Policies 

The RMA is an industry association whose membership includes most major domestic and foreign manufacturers selling tires in the United States. The RMA collectively establishes the foundation of industry policies, from which the tire manufacturers can specify their company's exact position. 

The RMA makes available training presentations and workshop posters to assist tire technicians with the steps necessary to properly repair tires. Each tire manufacturer specifies RMA tire repair procedures must be followed precisely to have any tire repair deemed proper. 

While basic RMA tire repair procedures remain the same for run-flat tires as non-run-flat tires, many tire manufacturers had issued specific policies that supersede RMA's standard reparability policies. 

Selected Tire Manufacturer's Policies for Run-Flat Tire 

Repair The following list summarizes tire manufacturers' repair policies, however it should be noted that every tire manufacturer that consents to repair, does so only after the punctured tire has passed a thorough exterior and interior examination.

Manufacturer/Brand	Repair Policy	Additional Provisions
BFGoodrich	Permitted	1 repair maximum
Bridgestone	Permitted	Only if 15 psi maintained
Continental	Does not recommend	Mfg. Road Hazard Program*
Dunlop	Permitted
Firestone	Permitted	Only if 15 psi maintained
Goodyear	Permitted
Kumho	Permitted
Michelin	Permitted	1 repair maximum
Pirelli	Not endorsed	Mfg. Road Hazard Program**
Yokohama	Not to be repaired	Mfg. Road Hazard Program***

Replaced free of charge first year or first 2/32" of wear (whichever comes first). Continental advises that a repair to one of its tires invalidates all other manufacturer's warranties.

 Replaced free of charge first year or first 2/32" of wear (whichever comes first), then prorated until worn to 2/32" of remaining tread depth 

5-year prorated replacement until worn to 2/32" of remaining tread depth if punctured in RMA defined repairable area 

Use of run-flat tires deemed non-repairable may result in vehicle or property damage, as well as can cause personal injury or death.

Driving on Flat Run-Flat Tires

Run-flat tires offer drivers temporary extended mobility even after a puncture allows complete air pressure loss. However, even run-flat tires will fail if driven too fast, too far or too heavily loaded when flat.

 For this reason, run-flat tires may only be used on vehicles equipped with a Tire Pressure Monitoring System (TPMS) that alerts the driver if one or more tires have lost 25% of their recommended inflation pressure. Illumination of the TPMS warning light identifies that at least one tire is losing/has lost air and establishes the beginning of the extended mobility range the driver can carefully continue driving to escape inclement weather, unsafe surroundings or insufficient visibility, etc. 

Note that a run-flat tire's endurance is dependent on operating conditions such as the flat tire's position on the vehicle, vehicle load, ambient temperature, driving speed and distance traveled. Run-flat tires cannot be driven faster then 50 miles per hour and typically offer up to 50 miles of extended mobility. Selected applications, based on vehicle and the run-flat tire design can range from just 25 miles up to 200 miles. Consult your vehicle owner's manual to determine what you should expect. 

Vehicle handling with run-flat tires at zero pressure is different than at full pressure, too. Aggressive acceleration, cornering and braking should be avoided, as well as any unusual service conditions such as carrying heavy loads or towing a trailer. 

Most tire manufacturers recommend replacement of run-flat tires that have been driven after the TPMS light has illuminated. Run-flat tires driven with low or no air pressure may have experienced irreparable internal structural damage that is not visible in a non-destructive examination. While most run-flat tires offer a promise of temporary extended mobility at speeds up to 50 miles per hour, Tire Rack recommends driving the slowest safe speed below 50 miles per hour, and the shortest distance to a service facility.

Dangers of Mixing Tire Tread Depths

When Buying a Pair of Tires It's best to replace all of a vehicle's tires at the same time. Having the same tread design and tread depth promotes balanced traction and handling. 

However if only a pair of tires is replaced, the two new tires are to be installed on the rear axle with the partially worn tires on the front. This is done to reduce the likelihood of drivers losing vehicle control when tires hydroplane on wet roads.

Hydroplaning can occur when driving through rainstorms or standing water. If water can't flow from under a tire's tread pattern, it can lift the tread until it loses contact with the road. Tires with less tread depth will hydroplane in shallower water and at lower speeds than tires with deeper treads.

 Whether the front or rear tires hydroplane first can make all the difference. 

Hydroplaning front tires promote understeer, a condition in which a vehicle continues forward. Most drivers' natural instinct to lift off the throttle causes an understeering vehicle to slow and helps the front tires regain traction. 

Hydroplaning rear tires promote oversteer, a condition that reduces vehicle stability. If rear tire hydroplaning causes a vehicle to oversteer, lifting off the throttle will further reduce stability, possibly causing the rear of the vehicle to slide, fishtail or spin. 

It's easier for drivers to control understeer; whereas trying to neutralize oversteer is far more challenging. It's better to sacrifice some grip up front rather than at the back. 

When installing a pair of new tires instead of four, Tire Rack's policy is to make sure the new tires are appropriately sized and compatible with the performance category of the current tires. The pair of new tires will then be installed on the vehicle's rear axle.

Notes: Applies to front-, rear- and all-wheel drive vehicles. Some all-wheel drive vehicles also require matching tire tread depths to prevent driveline damage. Minor differences in tread depths between front and rear tires (up to 2/32") are allowable and permit rotating tires.

Michelin Green X technology

Manufacturing tires for practically every type of consumer vehicle from cars, vans and crossover vehicles to full-size pickups and sport utility vehicles, Michelin has long been committed to better mobility through the "sustainability of the planet and society over the long term.

" While many drivers favor environmentally friendly mobility, most are unaware of how tires influence their vehicle's energy efficiency and environmental impact.

 "[The Green X] is Michelin's guarantee that the tire provides a level of energy efficiency among the highest in the market for its category without compromising other key characteristics, such as traction and treadwear." 
Regardless of the source of power (gasoline, ethanol, diesel, hybrid or plug-in electric), energy is needed to keep a vehicle moving. Lowering tire rolling resistance by optimizing a tire's weight, internal structure, tread design and tread compound makes it possible to reduce vehicle energy consumption, as well as the CO2 emissions and other greenhouse gases emitted by fossil-fuel engines.

 Many of Michelin's most fuel-efficient Original Equipment (O.E.) and replacement tires are branded with their Green X symbol to provide visual confirmation of the tire's positive contribution to vehicle fuel efficiency and the global environment. 

The application of the Green X symbol is determined by laboratory testing on a model-by-model, size-by-size basis. It is Michelin's guarantee that the tire provides a level of energy efficiency among the highest in the market for its category without compromising other key characteristics, such as traction and treadwear. Note: Michelin tires branded with the Green X symbol are identified as such on their SPECS page.

马币持续贬值，轮胎售价10月调涨！

今年初因原产品价格下滑，轮胎价格下调，即使政府落实消费税，轮胎价格仍能保持不变，唯独这一波的马币贬值冲击，促使马币兑换美元而令到营运成本调高，预料10月，轮胎价格会上调5至10%。森美兰轮胎商公会会长黎日森指出，由于制造轮胎的原料价格以美元交易，然而马币不断贬值，导致轮胎成本提高，制造厂商已决定会在近期内宣布起价。
“轮胎制造厂商已向业者透露，成本较低的轮胎存货有限，他们必须调涨成本较高的轮胎价格，首当其冲的就是进口轮胎品牌，包括来自泰国、中国与印度等国家的产品。”他表示，轮胎的种类很多，涨幅相信从5至10%不等，而我国对进口轮胎的需求量相当多，包括Continental、Dunlop、Silverstone、Bridgestone与Goodyear等品牌。
“其实，轮胎价格于今年年头因原产品和石油价格下跌等因素而一度调降，实施消费税后也因10%税收统一为6%而没有降价，然而如今马币贬值难以回升，外国厂商吃不消而决定起价。”他指出，待现有的较低价轮胎存货卖完后，所有的新货就会涨价。至于本地制造的轮胎，则因仍有很多存货，相信暂时不会涨价。

Michelin Total Performance

Michelin Total Performance identifies the company's global strategy of developing tires capable of simultaneously delivering superior levels of performance in the key areas of safety, fuel efficiency, grip, longevity and durability. Through Michelin Total Performance, Michelin is maximizing tire performances by developing tires that reach for higher and more sweeping levels of innovation than previously imagined.

 Maximizing multiple tire performances requires overcoming challenges in design opposition.

 An example is the conflict that exists in increasing tread life while reducing fuel consumption. The easiest way to extend tire life is to add more rubber to the tread, but this negatively impacts fuel efficiency as more rubber means more weight and greater rolling resistance.

 Dry and wet grip performance is another example of design opposition. For dry conditions, it's optimal to have as much tread rubber in contact with the road as possible, as a slick tire does in racing. Conversely for wet conditions, it's necessary for tires to use patterned blocks and ridges to evacuate water and break up the surface film, allowing the rubber to grip the pavement to improve wet road handling and stopping distances. 

Michelin is committed to constantly improving all tire performance factors together rather than being easily satisfied with just doing well on one at a time — a challenging feat that Michelin achieves in unique ways through its innovative technologies. Resolving these conflicts with minimum sacrifice and achieving optimal tire performance exemplifies Michelin Total Performance.

Goodyear Fuel Max Technology

Goodyear Fuel Max Technology uses state-of-the art science to develop compounds and constructions that help reduce energy loss as a tire rolls. Goodyear initially incorporated Fuel Max Technology into commercial tractor/trailer tires and then expanded it into tires for family cars, vans, crossovers, SUVs and light-duty pickup trucks. 
Society of Automotive Engineer (SAE) tractor/trailer fuel consumption tests conducted in virtually ideal conditions have shown Goodyear commercial tires featuring Fuel Max Technology helps decrease fuel consumption by about 8% in comparison with standard production Goodyear tires (of course, tractor/trailers typically have 18 tires).
 Applying Fuel Max Technology to passenger car tires (Assurance Fuel Max) allowed Goodyear to retain long tread life while providing 27 percent less rolling resistance, which equates to a four percent improvement in fuel economy over the original Goodyear Assurance tire. And, applying Fuel Max Technology in crossover and sport utility vehicle tires (Assurance CS Fuel Max) provided a four percent improvement in fuel economy over Goodyear's Fortera Silent Armor. In essence, the greater fuel efficiency offered by both of these Fuel Max tire lines means drivers can save approximately 2,600 miles worth of fuel over the life of a set compared to standard tires.
 Many fuel-efficient tires depend on replacing carbon black material with silica in the tread compound to minimize rolling resistance. Fuel Max Technology introduced a proprietary fuel-saving tread compound that has been developed at the molecular level to yield improvements in rolling resistance while retaining or even enhancing tread life and traction.
 At the heart of Goodyear's new tread compound is a blend of polymers, which help improve silica dispersion and enhance the overall physical properties of the tread. The marriage of Fuel Max tire construction and this proprietary tread results in tires that help provide excellent fuel efficiency, as well as confident wet and dry traction, and long tread life.

Continental tire technology

Continental Tire EcoPlus+ Technology, EcoPlus or "E"
 Symbol 
(Continental Tire, one of Europe's largest Original Equipment tire suppliers, uses several naming conventions to identify its eco-friendly, fuel-efficient tires designed with low rolling resistance as one of their features.


EcoPlus+ Technology was introduced in North America during 2010 in conjunction with the Continental ProContact with EcoPlus+ Technology line of Standard Touring All-Season tires. EcoPlus+ Technology consists of two main ingredients: 
Tg-F Polymers: Temperature activated functional polymers that increase compound bonding thus improving treadwear and fuel efficiency.
 +Silane: +Silane additives enhance grip on slippery roads, therefore reducing stopping distances.

EcoPlus
EcoPlus branding has been used to acknowledge the lower rolling resistance of selected Continental Original Equipment tires fitted to European roadsters, coupes and sedans. EcoPlus was introduced in North America during the 1990s in conjunction with the Continental ContiTouringContact CH95 line of Grand Touring All-Season tires, and has since been expanded to include ContiTouringContact CT95, CV95 and CW95 tire lines. 

"E" Symbol
 While Continental Original Equipment tires typically feature fuel-efficient constructions and compounds to help the vehicles they are fitted to meet government CAF� and/or CO2 emission requirements, Continental's wide range of Original Equipment fitments has created a need to be able to differentiate "standard" from "optimized" rolling resistance tires. 
Therefore, where multiple versions of the same tire size, tread pattern and service description exist, additional versions that offer significant reductions in rolling resistance will be identified with an "E" symbol following the tire line name. The "E" symbol is printed on the tire label and branded on the tire sidewall. An example is the standard ContiSportContact 3 SSR tires compared to the ContiSportContact 3 E SSR tires used as Original Equipment on BMW 5 Series cars beginning with the 2011 model year. 

Note: It is not recommended to mix standard and "E"-symbol "optimized" rolling resistance tires on the same vehicle.

Tire / Rim Protectors

Photo #1 - No Protection

While curbs and debris on the road have never been considered a tire's friend, many of today's tires resist accidental damage by featuring thicker rubber molded at key locations on their sidewalls. This helps reduce damage to the tires and/or wheels when drivers accidentally rub them against curbs while parking or turning sharply out of a driveway.

 However, most standard tires don't feature rim protectors of any kind (Photo #1) because they are frequently mounted on steel wheels. While this may initially appear to be an oversight, it is really done to accommodate the reality that most steel wheels use hubcaps to provide a more desirable appearance. The absence of a rim protector allows more flexibility in hubcap styling and how hubcaps are designed and attach to the wheel.

 The tires that feature tire/rim protectors use several different designs. Many of these tires feature a raised rib adjacent to the bead area on their lower sidewalls or have a deeply recessed bead area to partially envelop the wheel flange. Other tires feature raised ribs at the tire's maximum section width (the distance between a tire's sidewalls measured at the widest part of the tire). 

Tires featuring the raised rib adjacent to the bead (Photo #2) or the deeply recessed bead area (Photo #3) are designed to help protect low-profile tires and expensive alloy wheels from accidental curb damage. While tires featuring the raised rib or molded recess design will often thwart the use of wheel covers, this typically isn't a problem since these tires are customarily used on vehicles equipped with alloy wheels.

Photo #2 - Raised

Photo #3 - Recessed

In light truck off-road applications, the rim protectors will also help shield the tire and wheel bead area from debris, as well as resist damage inflicted by rocks, tree stumps and other off-road obstacles.

Photo #4 - Scuff Guard

Storing Tires

Since heat and exposure to the elements are the important factors that influence a tire's aging process, drivers can prolong their tire's life by minimizing their impact. Here are some tips for storing tires that will not be used continuously.

• Don't store a vehicle with weight on its tires for extended periods of time. Long-term inactivity is more harmful to tires than weekly drives that flex the tires and help maintain oil dispersion within the rubber compounds.
• Keep the tires out of direct sunlight whenever possible. The sun's ultraviolet rays and radiant heat are detrimental to rubber. We have used a pyrometer to measure tires that were simply sitting in direct sunlight on a parked vehicle. Surprisingly those tires' temperatures measured 135° Fahrenheit on their surface.
• Before storing, use a tire brush to clean each tire with soap and water to remove brake dust, dirt and grime. If the tires are still mounted on wheels, use a wheel brush to clean the wheels with an approved cleaner as well. Dry with a towel and let any remaining moisture thoroughly evaporate.
  DO NOT APPLY ANY TIRE DRESSINGS. Tire compounds are formulated to resist ozone cracking or weather checking.
• Place each clean and dry tire in its own large, opaque, airtight plastic bag (such as lawn and garden bags) for storing. Avoid allowing any moisture to remain and remove as much air as practical (some drivers even use a vacuum cleaner to draw out as much as possible). Close the bag tightly and tape it shut. This places the tire in its own personal mini-atmosphere to help reduce oil evaporation.
• While Seasonal Tire Totes make it neater to store tires, easier to carry tires and reduce the possibility of depositing brake dust, dirt and grime in the trunk or on the back seat during transportation, Seasonal Tire Totes are not airtight nor designed to prevent exposure to the atmosphere. The recommended solution would be to place each clean tire and wheel into the airtight plastic bag and then cover the sealed bag with a Tire Tote.
• If you choose not to store white letter/white stripe tires in plastic bags, it is important they be stored or stacked white-to-white and black-to-black to prevent staining the white rubber. The black rubber used on the tires' white letter/white stripe side is compounded differently then the black rubber used on the opposite side. A layer of non-staining black rubber covers the white rubber on the tire's white side to prevent oils in the tire from migrating into the exposed white rubber and discoloring it; however the black sidewall uses standard rubber. Stacking all tires white sidewall up will allow the oils from each tire's black sidewall to migrate into the white rubber of the tire below it.
• Place the tires in a cool, dry location. It is better to store tires in a dry basement or climate-controlled workshop than in a standard garage, storage shed, hot attic or outdoors. While basement and shop surroundings tend to remain cool and dry, conditions found in typical garage, shed, attic and outdoor locations often include a wide range of hot and cold temperatures, as well as seasonal precipitation and humidity.
• Keep the tires away from sources of ozone. Electric motors that use contact brushes generate ozone. Keep your tires away from the furnace, sump pump, etc.

While tires will age somewhat regardless of what precautions are taken, these procedures will help slow the process compared to taking no precautions at all.

Air Pressure: When & How to Set

Maintenance Tips to Increase Tire Performance, Life and Durability 

Check and Adjust First Thing In The Morning. Set according to the vehicle manufacturer's cold tire pressure(s) recommended on the vehicle's tire placard or in its owner's manual. This must be done before rising ambient temperatures, the sun's radiant heat or even driving short distances temporarily warms the tires. 

Check and adjust first thing in the morning...before rising ambient temperatures, the sun's radiant heat or even driving short distances temporarily warms the tires.

Accommodating Variables

 Indoor-to-outdoor Temperature Variation. Significant differences between the conditions tire pressures are set (the warmth of an attached garage, heated garage or service shop) and in which the vehicle will be driven (winter's subfreezing temperatures) requires inflating tires 1 psi higher than recommended on the placard for every 10° F difference in temperature between interior and exterior temperatures. 

Afternoon Ambient Temperature Increase.* Set 2 psi above vehicle manufacturer's cold inflation recommendations when installing new tires or if the vehicle has been parked in the shade for a few hours. 

Tire Heat Generated While Being Driven (or at speeds of less than 45 mph).* Set 4 psi above vehicle manufacturer's cold inflation recommendations. 

Heat Generated While Being Driven Extensively (or at sustained speeds greater than 45 mph).* Set 6 psi above vehicle manufacturer's cold inflation recommendations. 

Do Not Release Hot Tire Pressure if any of these variables could be the cause of measured tire pressure exceeding the maximum psi branded on the tire's sidewall by the 2, 4 or 6 psi indicated above for the various conditions. This temporary pressure increase is expected and designed into the tire's capabilities. 

Note: Tires on a parked vehicle exposed to direct sunlight will appear overinflated due to the heat absorbed from the radiant energy of the sun. Pressures cannot be accurately set on these tires until all have stabilized in the shade.

Spare Tire Use

If you ever visit an auto museum, you'll see most antique cars were equipped with two or more spare tires. Fortunately today's roads and improved tire durability have reduced that necessity, allowing our vehicles to be equipped with a single spare or none at all!

While some of today's vehicles are equipped with spares that match the other tires and wheels on the vehicle, they are in the minority. Now most vehicles are originally equipped with a "temporary-use" spare tire and wheel that probably differs in size and construction from the other tires and wheels on the vehicle. And some vehicles are even delivered without a spare tire and wheel thanks to the extended mobility provided by modern run-flat tires or temporary repair and inflation systems, like the ContiComfortKit.

Full-Size Matching Spare Tires and Wheels

While full-size matching spare tires and wheels require the greatest amount of storage space, they are the most versatile. Full-size matching spare tires and wheels should be integrated into the vehicle's tire rotation pattern from the beginning. This will essentially create a set of five tires that will last longer than just four, as well as will "wear out" the spare tire before it "ages out." If the vehicle has all-wheel or four-wheel drive, the spare tire will remain at a similar tread depth to the other tires on the vehicle, reducing driveline stress when called into service. Additionally, when it is time to replace the vehicle's tires, they can be replaced as a set of five allowing you to benefit from using the latest tire technology or select a more desirable tire size that fits the original wheels.

Many of today's spare tires are temporary spare designs intended to get the vehicle to a trained tire service person to repair or replace the tire that's been punctured or damaged.

Full-Size Temporary Spares

Full-size temporary spare tires and wheels match the vehicle's original tire dimensions, but typically feature lighter-weight construction and a shallower tread depth to reduce vehicle weight to improve fuel economy and make the spare easier to install. While most of today's vehicles are originally equipped with alloy wheels, full-size temporary spares are typically mounted on steel wheels and should be used only as spares.

Temporary/Compact Spares

Temporary/Compact Spare tires are physically shorter and narrower than the vehicle's standard tires and wheels. Their smaller dimensions require they operate at higher inflation pressures (typically 60 psi) than standard tires. Temporary/Compact Spares also feature lighter-weight construction and a shallower tread depth than standard tires to reduce vehicle weight, as well as allow more trunk space to be dedicated to luggage. The compact temporary spare tire and wheel that comes with a vehicle is designed to fit that vehicle only. Never attempt to use a Temporary/Compact Spare Tire and wheel on another vehicle unless it is the exact same make and model.

Folding Temporary Spares

While folding temporary spare tires have been installed in vehicles previously, they have extremely limited application today. Folding spares provide the greatest space savings but are more complex to use because they must be inflated with an air pump or a canister of pressurized air prior to use.

The Following Tips Can Help Make Sure That Your Spare Is Used Correctly and Safely

Learn how to install the spare on your vehicle before you have to. Learn how to access the spare tire, jack, lug wrench and wheel lock key (if equipped). Confirm where the jack is to contact the vehicle and practice changing a tire. This will make it a lot easier on that cold, dark rainy night when your vehicle has a real flat.

All temporary spare tires are designed for short-term use only; they are not designed with the same capabilities in terms of load capacity, speed capability, or all-weather traction.

Always check your vehicle's owner's manual and the temporary spare's sidewall for instructions on proper use. It is also important to recognize that controlling a vehicle may be more difficult when using a temporary spare, and temporary spare tires are usually accompanied with warnings that advise against towing a trailer, or traveling over 50 miles per hour for further than 50 miles.

Check the spare tire's air pressure with a tire pressure gauge on a monthly basis, when you check all other tires on the vehicle. There's nothing more aggravating than a flat spare when you have a flat tire.

Always confirm the inflation pressure before use and ensure that your spare has the manufacturer recommended inflation. It's important to check and adjust the temporary spare's inflation to the recommended pressure before driving away.

Selecting the Right Tires

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 the Tire Rack 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 the Tire Rack is always ready to offer performance and fitment advice. Call 888-541-1777.

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 a 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. 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.

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 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 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?

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 5/32" 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.