Q. How much air should I put in my tires?
A. Proper air pressure is the most important part of tire care. Tires should be inflated to the pressure recommended by the manufacturer of your car. The vehicle manufacturer’s recommended tire size and inflation pressure are shown in the owner’s manual. This information is also placed in one or more of the following areas:
- On the edge of the driver’s door.
- On the door post.
- On the inside of the glovebox door.
If the tire size on the vehicle does not match the recommended size, consult a Goodyear Representative or Goodyear Dealer.
UNDERINFLATION
Underinflation is a tire’s worst enemy. An underinflated tire can experience excessive sidewall flexing which results in high heat generation and a reduction in fuel economy. Inflating your tires to the maximum pressure specified on the tire sidewall can extend tire life and improve your fuel economy.
CHECK INFLATION REGULARLY
You cannot determine whether a tire has the correct air pressure just by looking at it. This is especially true with radial tires. You should check tire pressure with a good quality air pressure gauge at least every two weeks and before any long trips. Always check the pressure when the tires are cool (when the vehicle has been driven less than one km.). If the car has been driven, allow the tires to cool for a few hours before checking the pressure.
Never bleed or reduce tire pressure when tires are hot. A tire’s air pressure will automatically increase as its internal temperature increases. This increase is normal and should not be adjusted.
VARY INFLATION WITH LOAD
Tire pressure should be increased when your car is carrying extra weight, such as on a vacation trip. An increase of 4 psi over the car manufacturer’s recommended cold tire pressure is usually adequate.
Remember, check and adjust inflation only when tires are cool.
Q. Why should I rotate my tires?
A. The purpose of regular tire rotation is to achieve more uniform wear for all tires on a vehicle. Before you rotate the tires, consult the vehicle owner’s manual for the manufacturer’s rotation recommendation. If no rotation period is specified, tires should be rotated every 10,000 to 12,000 kilometers. The first rotation is the most important.
If the tires show uneven wear, ask a serviceman to check and correct any misalignment, imbalance, or other mechanical problem before rotation. Manufacturers often recommend different inflation pressures for the front and rear tires. When tires are rotated, inflation pressure must be adjusted to the vehicle manufacturer’s recommendations.
The rear tires on the front wheel drive vehicles may exhibit irregular wear due to the light loads on the rear axle or misalignment of the rear axle. Regular tire rotation will minimize uneven wear conditions.
The front tires on front wheel drive vehicles may exhibit faster wear than the rear tires because they carry most of the weight and do most of the work. To obtain more even wear, the tires may be rotated so all four tires wear out at approximately the same mileage. Check your vehicle owner’s manual for the recommended rotation.
Q. Some people say I need to have my wheels balanced. Why?
A. If a tire and wheel assembly is not balanced, uneven weight distribution may cause an unacceptable vibration. This will affect your riding comfort and may affect the overall performance of your tires. Uneven weight distribution is corrected by adding precision weights at the proper locations around the wheel rim. Dynamic (two plane) balancing reveals whether a tire/wheel assembly is unbalanced from side to side as well as about its center. Dynamic imbalance can result in vibration and, sometimes, a steering wheel sensation called shimmy.
Most modern tire service locations use off-the-car computer balancers which correct for both static (single plane) and dynamic (two plane) imbalance.
Note: Radial tires should always be dynamically balanced.
Q. When should wheel balancing be done.
A. Tires and wheel should be balanced:
- When a new tires are mounted on wheels for the first time.
- When tires and wheels are rotated.
- When used tires are mounted on existing wheels.
- After flat repair.
- Any other time a tire is dismounted and remounted.
Balance should also be checked at the first sign of vibration, shimmy, or unusual treadwear. Any noticeable vibration or irregular treadwear should be taken to a professional for diagnosis.
Q. How important is alignment for longer tire life?
A. A quality alignment is mandatory for even treadwear and proper handling. Front and rear tires should be checked periodically for signs of uneven wear. A change in handling or steering feel can indicate that an alignment is needed.
Q. Just what is alignment, anyway?
A. A vehicle is said to be properly aligned when all suspension and steering components are sound, and when the tire and wheel assemblies are geometrically set to run straight and true.
Automotive suspension systems involve moving parts so wear of steering and suspension components is normal and is expected. As these components wear, however, alignment changes and has to be adjusted to bring the setting back into the specification range. Whatever the cause of misalignment, the result is that the tires do not roll as straight as they should. This causes scuffing, uneven, and (sometimes) rapid treadwear.
Q. Why “vehicle alignment?” Is that the same as “front-end” alignment?
A. Cars have changed. Modern suspension, steering, and drivetrain design all require a total vehicle, four-wheel approach to alignment for proper performance.
Many vehicles today are equipped with a rear suspension design that require an alignment check and possible adjustment. A misaligned rear suspension may cause problems for both front and rear tires.
A common rear wheel alignment problem is an apparent crooked steering wheel that results from an excessive thrust angle (dog tracking). Too large a thrust angle can make it feel as if the vehicle is travelling slightly sideways and may require the steering wheel to be turned to keep the vehicle moving straight ahead.
Q. Any discussion of alignment usually involves three terms: caster, camber and toe. What is toe?
A. Toe describes the measured distance between the front of the two tires. The objective of proper toe is to make the tires roll essentially parallel to one another and thus, minimize wear.
Excessive toe-in causes a feather edging type of wear on the outside edges of the tire tread. Toe-out causes the reverse: feather edging of the inside shoulder edges. Radial tires may show other types of wear as a result of improper toe.
Incorrect toe can cause irregular wear around the tire, or a diagonal wiping type of wear across the tread.
Q. What is camber?
A. Camber is the tilt of the top of a wheel inward (toward the vehicle or outward away from the vehicle).
Proper camber, in combination with toe and caster, assures that the tread is as flat against the roads as possible under all driving conditions.
Too much positive camber causes accelerated wear on the outside edge of the tire. Camber can be positive on one wheel and negative on the other wheel of the same axle. Or it can be negative (or positive) on both wheels on the same axle.
Q. What is a caster?
A. Caster is the forward (negative) or rearward (positive) tilt of the spindle steering axis on a car. Correct caster on a vehicle is never perfectly vertical, but is always set on a slight angle.
The basic purpose of caster are:
1.) to maintain directional control.
2.) to give a more on-center feel to steering
3.) to return the vehicle to a straight ahead position when exiting a turn.
Insufficient caster can cause wander or a light feeling in the steering. Excess positive caster can cause hard steering in extreme cases. Unequal caster can cause the vehicle to pull toward the side with the least positive caster.
When caster is out of the manufacturer’s specification range, tire wear may occur because the wheel has an incorrect camber on turns. However, loose or worn steering or suspension parts that would produce an incorrect caster angle would also effect camber and toe. These, too, would lead to tire wear.
Recommended Alignment Specifications
Toe-in Set to the preferred setting recommended by the vehicle manufacturer, both front and rear.
Caster Set to the preferred setting within the tolerances specified by the vehicle manufacturer.
Camber Set to the preferred vehicle manufacturer’s specification.
Q. How can I check my tires for wear problems?
A. Tires often give their owners signs of problems in plenty of time to have them corrected. You can easily read these early warning signs by looking for:
A Sawtooth Appearance On The Edges
This is usually caused by erratic scrubbing against the road when a tire is in need of a toe-in or toe-out alignment correction.
Faster Wear On The Outer Edges Than In The Middle
When a tire is underinflated, more of its contact with the road is on the outer tread edges or the shoulder. Thus, there areas wear faster than the middle. Be sure to check the tire’s air pressure.
The Tire Wears Excessively On One Side
Camber or toe-in misalignment, which places too much of the work on one side of the tire, is usually to blame for one-sided wear. An alignment correction is required.
Cups or Dips In The Tread
Many things can cause this kind of irregular wear. Misalignment or worn suspension components are the most likely causes.
Excessive wear in the middle is a tell-tale sign of an over inflated tire.
Q, Is there a simple test for tread wear?
A. In addition to visually inspecting your tires for wear, here’s simple test you can perform to measure the tread depth on your tires. Place one peso coin into a tread groove with the ”1” peso mark upside down and facing you. If you see the top of the ”1” mark you need a new tire.
Q. Must I replace m present tires with the same size tires?
A. Never choose a smaller tire than the size that came with the car. Smaller tires may not be able to support the loaded weight of the vehicle. Tires should always be replaced with the same size designation-or the approved options-recommended by the auto or tire manufacturer.
Q. Can I mix tire types on my car?
A. Tires with different size designations, constructions, and amounts of wear may affect vehicle handling and stability. For best all-around performance, the same type tire should be used on all four wheel positions. Special purpose tires (such as snow tires) can be used to improve performance in some applications. Some tires, such as speed rated constructions, may also have special matching requirements.
It is possible to mix your present tires with other size designations or constructions. However, tires of similar size and similar construction must be used in pairs on the same axle. When radial tires are used with bias or bias belted tires on the same car, the radials must always be placed on the rear axle.
Q. What should I do if I notice a vibration?
A. Vibration is an indication that something needs attention. If corrected promptly, the problem may only require a minor adjustment to correct the vibration. If neglected, the vibration could cause accelerated wear or damage to tires, steering and suspension components.
Whenever vibration occurs, the tires should be checked for any irregular wear. The type of wear can help to determine the possible cause and probable correction of the vibration.
Q. Can my driving habits affect the life of my tires?
A. They certainly can! To increase the life of your tires you must avoid bad driving habits such as:
- Fast starts and panic stops
- Fast turns on curves and around corners.
- Riding on the edge of the pavement, driving over curbs, chuckholes, or other obstructions.
Aggressive driving leads to abrasive treadwear and generates additional stress in tire sidewalls and shoulders. These can lead to premature wearout or failure of the tire.
Road hazards are a leading cause of premature tire removal. Driving over road debris or obstacles or hitting curbs can cause tire damage. This damage may be visible cuts or tears in the sidewall or tread, or hidden internal damage which may cause problems later.
In addition, hitting road hazards can jar suspension and steering components out of alignment. This misalignment may lead to the tire wear discussed previously.
Q. Is it safe to repair a flat tire?
A. If a tire loses all or most of its air pressure, particularly at highway speeds, it must be removed from the wheel for a complete internal damage inspection. Tires that are run even short distances while flat are often damaged beyond repair.
Most punctures, nail holes, or cuts (up to 1/4-inch) in the tread area may be satisfactorily repaired. Only trained personnel, using industry approved methods and materials, should repair a tire. Repairs must always be made from the inside of the tire to fill the injury and seal the inner line.
Your best bet is to make sure your spare tire is always ready to do the good job. Check it regularly for proper air pressure and be sure that it is in good shape.
Q. How should I store my extra tires?
A. Extra tires should be stored flat on a smooth, oil-free floor. Plastic tire storage bags are practical and convenient.
Pick a spot in your garage or basement that is cool, clean, dry, sunless, and away from strong air currents. DO NOT STORE YOUR TIRES WITH OR NEAR ELECTRIC MOTORS. Motors generate rubber-damaging ozone gas.
Stacking a black side wall against a white one can permanently stain the white sidewall. If you have white sidewalls, place plastic or cardboard between the tires or stack them white-to-white only.
Note: Extended storage of a vehicle may require special precautions to prevent flatspotting of the tires. If possible, remove the load from the tires. Otherwise, move the vehicle occasionally (once a month is OK) so a different spot on the tread is touching the ground.
