11/22/2025
With the discontinuation of pennies, we felt it a good time to explain the curious relationship between pennies and tires…have you heard of using a penny to check your tires? Have you wondered why? If you answer yes to either one of those, here is the reason. Using a very accurate tread depth gauge, you can see in picture 2 that Lincoln’s hair is at 2/32”. For decades that has been the threshold that when passed indicates your tires are legally “bald”. Tires have built in indicators called “wear bars” which are raised ribs in the tread groves at 2/32”, however, they are difficult to see at times. Over the last decade some manufactures have stamped tread depth numbers in the tread at the appropriate depth…but again, tough to see. One can, and should have a tread depth gauge as part of their car maintenance kit, but let’s be honest, most people don’t have that or forget what is in it. What you most people have rattling around their pocket, console, cup holder, ash tray..? That’s right, some Lincoln head pennies. While never exact, it’s a good quick way to check your tire’s tread depth. Over the years there have been changes to tread depth laws. Commercial trucks are required to have 4/32” tread on steer (front) tires. Many states charge tread requirements seasonally. Colorado is one of those states. 9/1-5/31 each season all vehicles are required to have 4/32” tread depth in most of the State most of the time. I-70 from about Golden to about Grand Junction the requirement is 6/32”. If weather conditions and road conditions deteriorate then State Patrol can dial up the requirement from 4 up to 6/32” in those impacted areas. Alas, this renders the hair of our 16th president useless and with no more pennies being minted, people will be without a handy point of reference. This means it’s time for a tread depth gauge…or, some of our new business cards with an overview of the Colorado traction law AND a “built in” tread depth gauge. Fits in your wallet, purse, glovebox, or stuck to your refrigerator. When you run out of pennies, or decide to become a collector, come by American Tire Exchange, Inc. and we will check out your tires and show you how to use this gauge.