Inspect the tires regularly for wear and damage. Remove stones or other foreign particles which may be lodged in the tread. If tread wear is excessive or irregular it could be a sign of front end problems, or simply improper inflation.
The inflation should be checked at least once per month and adjusted if necessary. The tires must be cold (driven less than one mile) or an inaccurate reading will result. Do not forget to check the spare.
The correct inflation pressure for your vehicle can be found in the owner's manual and on a decal attached to the vehicle. Depending upon model and year, the decal can be located at the driver's door, the passenger's door or the glove box. If you cannot find the decal, inspect the sidewall of the tire. Most manufacturers provide tire inflation pressures on the tire.
Inspect tires for uneven wear that might indicate the need for front end alignment or tire rotation. Tires should be replaced when a tread wear indicator appears as a solid band across the tread.
When you buy new tires, give some thought to these points, especially if you are switching to larger tires or to another profile series (50, 60, 70, 78):
- The wheels must be the correct width for the tire. Tire dealers have charts of tire and rim compatibility. A mismatch can cause sloppy handling and rapid tread wear. The old rule of thumb is that the tread width should match the rim width (inside bead to inside bead) within an inch. For radial tires, the rim width should be 80% or less of the tire (not tread) width.
- The height (mounted diameter) of the new tires can greatly change speedometer accuracy, engine speed at a given road speed, fuel mileage, acceleration, and ground clearance. Tire makers furnish full measurement specifications. Speedometer drive gears are available from Ford dealers for correction.
Dimensions of tires marked the same size may vary significantly, even among tires from the same maker.
- The spare tire should be usable, at least for low speed operation, with the new tires.
- There should not be any body interference when the vehicle is fully loaded, on bumps, or in turning.
The only sure way to avoid problems with these points is to stick to tire and wheel sizes available as factory options.
See Figure 1
Tires should be rotated periodically to get the maximum tread life available. A good time to do this is when changing over from regular tires to snow tires, or about once per year. If front end problems are suspected, have them corrected before rotating the tires. Torque the lug nuts to 80-105 ft. lbs.
Avoid overtightening the lug nuts to prevent damage to the brake disc or drum. Alloy wheels can also be cracked by overtightening. Use of a torque wrench is highly recommended. Tighten the lug nuts to specification in a criss-cross sequence.
The pattern you use depends on whether or not your car has a full-sized usable spare or a undersized "donut'' spare. Because the compact or donut spare tire is designed for limited emergency use, it should not be included in normal tire rotation.
Due to their design, radial tires tend to wear faster in the shoulder area, particularly in the front positions. Radial tires in non-drive locations, may develop an irregular wear pattern that can generate tire noise. It was originally thought the radial tires should not be cross-switched (from one side of the car to the other); because of their wear patterns and because they would last longer if the direction of rotation is not changed. Of course, the tire manufacturer's rotation recommendations should always be followed, but many manufacturers now allow for, and even suggest, cross-switching radial tires to allow for more uniform tire wear.
Some specialty aftermarket tires may be directional (certain snow or high performance tires), meaning they may only be mounted to rotate in one direction. Some snow tires and special performance tires/wheels will fall into this category and will be marked with directional rotation arrows on the tire sidewalls. NEVER switch the direction of rotation on tires so marked or poor performance/tire damage could occur. This should be taken into consideration in choosing a rotation pattern for directional tires.
All 4 tires should be of the same construction type. Radial, bias, or bias-belted belted tires should not be mixed. The wheels must be the correct width for the tire. Tire dealers have charts of tire and rim compatibility. A mismatch can cause sloppy handling and rapid tire wear. The tread width should match the rim width (inside bead to inside bead) within an inch. For radial tires, the rim width should be 80%or less of the tire (not tread) width. The height (mounted diameter) of the new tires can greatly change speedometer accuracy, engine speed at a given road speed, fuel mileage, acceleration and ground clearance. Tire manufacturers furnish full measurement specifications.
Store tires at proper inflation pressure if they are mounted on wheels. All tires should be kept in a cool, dry place. If they are stored in a garage or basement, do not let them stand on a concrete floor. Rather, set them on strips of wood.
The tires should be checked frequently for proper air pressure. Make sure that the tires are cool, as you will get a false reading when the tires are heated because air pressure increases with temperature. A chart in the glove compartment or on the driver's door pillar gives the recommended inflation pressure. Maximum fuel economy and tire life will result if pressure is maintained at the highest figure given in the chart. When checking pressures, do not neglect the spare tire. The tires should be checked before driving, since pressure can increase as much as 6 pounds per square inch (psi) due to heat buildup.
Some spare tires require pressures considerably higher than those used in other tires.
While you are checking the tire pressure, take a look at the tread. The tread should be wearing evenly across the tire. Excessive wear in the center of the tread could indicate over inflation. Excessive wear on the outer edges could indicate under inflation. An irregular wear pattern is usually a sign of incorrect front wheel alignment or wheel balance. A front end that is out of alignment will usually pull the car to one side of a flat road when the steering wheel is released. Incorrect front wheel balance will produce vibration in the steering wheel, while unbalanced rear wheels will result in floor, seat or trunk vibration.
It is a good idea to have your own accurate tire gauge, and to check pressures weekly. Not all gauges on service station air pumps can be trusted for accuracy.
Tires should be replaced when a tread wear indicator appears as a solid band across the tread.
CARE OF SPECIAL WHEELS
Aluminum is vulnerable to abrasive cleaners, detergents and alkalies. Maintenance of aluminum wheels includes frequent washing and waxing. Failure to heed this warning will cause the protective coating to be damaged. If a vehicle washing detergent has been used, or salt from sea water or road chemicals adheres, wash the vehicle as soon as possible. After washing the vehicle, apply body or wheel wax to the aluminum type wheels to prevent corrosion.
When cleaning the vehicle with steam, do not direct steam onto the aluminum type wheels. The finish on the wheels may be damaged.