The design and construction of your tires is the first safety feature you have protecting you on the road. A quick inspection of your tires when you fill up with gas is a good habit to have. You'll have a better idea of when your tires are no longer safe and it's time for a new set. Here is how your tires work to keep you safe and how to check them at each fill-up.
Basic Tire Design
Each tire manufacturer develops their own tire designs to grip the road. While the designs may look different, they all use the same basic elements.
- Lugs - This is the raised rubber portion of the tire and the only part of the tire that touches the road. Over time, the lug wears down until you no longer have enough tread to be safe. The height of the lug is the key sign that you need new tires.
- Voids - These are the open spaces that run around the tire next to the lugs. These spaces allow the lugs to flex back and forth as they grip the road. Without the voids, your tire would look bald and you'd have almost no gripping power on the road surface.
- Grooves - These are open channels that run across the tire. Their purpose is to push water out of the way of the tire so that it will grip the road. Without these channels, the tire might hydroplane on top of the water, losing traction and making you skid off of the road.
- Sipes - These are additional channels cut into the tire, sometimes at the time of the tire installation. They provide additional gripping power on the road and are most helpful in areas with frequent snow, ice or wet conditions where the extra traction is needed.
Inspecting Your Tires
When the lug has worn down to below acceptable minimums, you can begin to lose traction on the road. During your fuel up, you can quickly check your tires to make sure you have enough tread left to be safe. There are a number of ways to check your tire's tread depth.
Using the wear bar - A small strip of rubber runs across the tire at several points to indicate the minimum lug height to be safe. Compare the height of the lug next to the wear bar. If the lug is higher than the bar, your tires are still safe. If the lug is at or below the level of the wear bar, it's time for a new set of tires.
Using a penny to test the tread - Keep a penny handy in the car to do this test. Place the penny into one of the voids next to a lug with Lincoln's head facing down into the tire. If the top of his head is still covered, you still have a safe amount of tread. If you can see the top of his head, your tread is below minimum safe levels and it's time to head to a tire shop.
Get a precise measurement at a tire shop like Lee Tire. Most tire shops offer free tire testing with a device that measures the precise amount of tread you have left. They may be able to give you an estimate as to how much life you have left in a tire so you can plan your tire shopping budget accordingly.