Most drivers neglect their tires. The failure to maintain tires properly and monitor their wear has been the cause of incalculable suffering and pain. If one front tire blows, your car will swerve and/or roll over and you will not be able to control it. Please share the following with all members of your family.
WATCH FOR SIGNS OF IMMINENT TIRE FAILURE:
"Cupping'" - Uneven tread wear or flat spots - can indicate suspension problems which are allowing the tire to bounce as you drive.
Bulges, cracks, or cuts in the sidewall which can indicate internal damage.
* Uneven tread wear may indicate over- or under-inflation. Over-inflated tires will wear out sooner in the center. Under-inflated tires will wear out sooner on the edges. Neither is good.
* The proper pressure for your tires is determined by the weight of your vehicle. Do not go by any suggested tire pressures printed on the tire. Use your vehicle's owner's manual or the pressure pasted on your vehicle's doorjamb.
* Check the pressure monthly and immediately prior to any long drives, but don't use the tire gauge at the gas station, it may be inaccurate. Buy your own. I recommend one with a dial on it for easy reading. Check the pressure when the tire is cold (hasn't been driven). If low, determine how many pounds low and drive to the station. When you get there, the pressure will probably be higher because of heat. Go ahead and put in the number of pounds you determined at home.
* Have the tires rotated every 6,000 miles.
* Watch the depth of the tread. Stick the top of a penny in the groove. If you can see the top of Mr. Lincoln's head, the tread is 1/16" or less and you should replace the tire.
WHEN BUYING NEW TIRES:
If you are not drastically changing driving environments (i.e., moving from beach to snowy mountains) you will probably just buy the same tires you have. If you want to change manufacturers, the retailer will have a tire equivalency chart to help with your choice.
You don't need to understand the alphanumeric code that indicates the tire's size and make-up (see below if you insist) but you do want to be sure you know what it is so you buy the same.
As you shop, remember that Bob recommends that you never buy the cheapest anything. If something is the cheapest, there is a reason. You do not want tires which were manufactured in a shoddy manner. Also remember to ask about the "bottom line", "out-the-door" price, INCLUDING mounting and balancing.
Look on the sidewall at the last 3 or 4 digits of the serial number. They indicate when the tire was manufactured. The first 2 digits indicate the week of the year and the last 1 or 2 (1 for prior to 2000 - 2 for 2000 and later) indicate the year. This tells you how long the tire has been laying around.
If you have a 4-wheel-drive vehicle, all 4 need to be the same size. On 2-wheel-drive, it's OK for front and rear to be different sizes as long as both front are the same and both rear are the same.
You do want to know what the alphanumeric code means? OK:
Example: P185/60R14 82H
P - Passenger car. Light Truck tires will have LT
185 - The tire's width in millimeters
60 - The ratio of sidewall height to tire width. In the example, the sidewall's height is 60% of the tire's width. Do the math and you find this sidewall is 111 millimeters high.
R - Radial-ply. B would indicate bias-ply, but they're extinct.
14 - Wheel diameter in inches. This is tradition. Otherwise it would be in millimeters.
82 - The load index, tells how much load the tire will support. The bigger the tire, the higher the load index.
H - The speed rating. Don't be concerned if you tire doesn't have this - not all do. This is a European development. The most common ratings are:
S - Safe at sustained speeds up to 113 mph
H - 130 mph
V - 149 mph
Z - Over 149 mph