Whether due to poor maintenance or a tire puncture, low air pressure causes more tire failures than all other factors combined. The symptoms are easily spotted and often include a low or bulging sidewall accompanied by a pulling or vibrating feeling as you drive the vehicle. Maintain your tires by checking the pressure at least once a month and always before you go on a trip. If you do it yourself, check the pressure when the tire is "cold" (that is at least three hours since the vehicle has been stopped or before it's been driven one mile). Refer to the manufacturer's handbook or the tire placard in the vehicle for correct tire pressure. Find out why air pressure is so important.
Objects in the road, potholes, curbs or any structure that impacts your tire can potentially damage it beyond repair. Check for any unusual tire appearance after impact, especially in the sidewall. If a tire has been sufficiently damaged, a ride disturbance (pulling or vibration) will frequently develop. Even if you can't see any damage, have a trained professional inspect the tire by dismounting it and checking from inside.
Overloading a tire can cause excessive heat buildup, leading to tire failure (most frequently a blowout). A tire's load carrying capacity is listed on the tire's sidewall, and is also stated in the Service Description. For example, "92H" on the sidewall of a tire is an indication of load capacity and speed rating. Many popular sizes have more than one load carrying capacity.
Treadwear indicators are built into every tire to signal the end of its useful
treadlife. At this tread depth, a tire has lost virtually all wet weather
traction and is also more vulnerable to puncture.
Remember that a tire may be worn inconsistently from one edge to the other due to mechanical wear (alignment), and it is only as good as the area with the least tread. If the tread depth is 3/32" or less, the tire is due for replacement. Also, remember to have your tires properly rotated on a regular basis to avoid premature wear.
If you are stuck in the mud or snow, do not spin the tires excessively; this leads to rapid tire overheating and failure. Tire explosions and tread separations are the most common failures and can be disastrous under these conditions.
When you decide to buy just two tires, make sure they have the same ratings (speed and load carrying), because different tires can cause handling problems. If you choose to buy tires with lower speed ratings, have the higher speed rated tires rotated to the rear for optimum handling.
Proper tire mounting is critical to safety and ride quality. When done correctly, factors such as sidewall height, drop-center width, match mounting and bead lubrication are considered. More than one type of tire machine is required to handle the various tire designs.