Safe driving often depends on the condition of your vehicle's tires. How much does it take to find out what shape your wheels are in? Try one cent. Got a Lincoln penny? It's the perfect size for checking whether it's time to buy new tires. Here's how:
Pinch a Lincoln-head from the base, between your thumb and forefinger, so that the top of Lincoln's head and the words "In God We Trust" are showing. Next, Place the top of Lincoln's head into one of the tire tread grooves — try to measure in the lowest point within the tread. If any part of Lincoln's head is obscured by the tread, you're all set — you have a legal and safe amount of tread.
However, if you can see above Lincoln's head or any of the "In God We Trust" letters above his head, then you are ready for a new tire. Check your tires in several tread locations. Be sure to check both inner, outer and middle grooves of each tire, because tires can wear differently on each side, due to improper wheel alignment and/or low inflation.
This penny trick works because the distance between the rim and Lincoln's head is one-sixteenth of an inch — the minimum required tread depth. When your tire tread is lower than one-sixteenth, your vehicle can have handling problems in adverse conditions (rain, sleet, snow).
Now, if only buying new tires cost just a penny.