Ever wonder when to replace your worn car tyres? The performance of your car tyres is critical to the safety, performance and efficiency of your vehicle. Most tires are designed to provide similar performance throughout their lives. However, at some point they start to lose performance in terms of their traction and braking ability. Here are a few tips that should help you decide if it is time to start shopping for a new set of tyres and avoid spending more than you need to.

Look at the tread pattern. All tyres have what are called "tread wear bars". These are small bridges that form between your treads. Look at the tread pattern and you will see the beginnings of these bars start to form between the treads, or running across the tires. As the tyres wear, these bars will become flush with the tire's tread. At this point it is time to replace the tires.

• It is a good idea to rotate your tyres from front to rear in pairs. Take both front tires and move them to the rear and vice versa.
• On 4-wheel-drive or all-wheel-drive cars you should replace all four tires if it is recommended in your service manual. Differences in tire diameter can permanently damage differentials.
• If you see uneven wear on a front tyre, chances are that the front end is out of alignment. You should have this checked and rotate the tires to the rear if possible (some vehicles have different sizes on front than the rear). The tyres from the back should be fine and the uneven tires moved to the rear will start to correct themselves.
• Tyres do not wear perfectly evenly, so be sure to insert the coin at several points from the outside to the inside of your tyres. Tyres generally wear more on the inside but over-inflated tires will wear more in the middle.
• Test all of your tyres and if possible, replace them all at the same time. Mismatched tyres will not provide the same safety, performance and efficiency as a matched pair will.
• Keep your tyres properly inflated.

• If uneven tyre wear is extreme or if tyres wear out much faster than expected, have a competent shop check your suspension and correct as necessary before replacing tires. Improper alignment or worn suspension parts can dramatically shorten tire life.
• Be careful to buy tyres that are the right size and type for your vehicle and rims (wheels). Changing to low-profile tyres may require you to buy larger rims so that the outer circumference of the tyre remains unchanged. Incorrect tyre size or mismatched tread can also cause a low tire pressure warning to come on if the vehicle is equipped with a Tyre Pressure Monitoring System (TPMS).
• Tyres should never rub against the your fenders or any other part of your car. If your new tires rub during turns or when going over bumps, they don't fit, no matter how cool they look. Fix this before you suffer a blowout and crash.
• Be careful when rotating tires, and especially when moving tyres to different rims. Many modern tyres have a specific rotational direction and corresponding rotation method. Refer to your tire manufacturer or dealer for details.