Rising costs are sneaking into even the smallest corners of life—including how you maintain your car. Among the handy tricks you might’ve picked up as a new driver, like topping off wiper fluid or checking oil, was the classic penny test for tire tread. But times have changed, and automotive pros now suggest swapping that penny for a quarter. Here’s why this simple shift matters for tire safety, plus a quick guide to doing it right.
What Tire Tread Does and Why It Matters
Tire tread refers to the rubber surface that meets the road, carved with grooves and ridges for grip. According to Tony Markovich from TheDrive, this design isn’t just for looks—it’s what keeps your car steady on wet or slippery pavement. Over time, wear flattens these patterns, reducing traction and raising the risk of hydroplaning. Well-maintained tread, therefore, is your first defense against losing control in rough weather.
The Quarter vs. Penny Debate
For years, the go-to method for checking tread involved a penny. You’d slide it upside-down into a groove, and if Lincoln’s head peeked out, your tires were due for replacement. This pegged the safe tread depth at 2/32 of an inch—a standard Michelin still backs. However, experts argue this benchmark skimps on safety.
Now, outlets like AAA and TheDrive push the quarter test instead, targeting 4/32 of an inch as the minimum for secure driving. Markovich notes this cautious approach better protects you on the road. With tire replacement costs climbing, ensuring you swap them out at the right time saves you from bigger headaches later.
How to Test Tire Tread with a Quarter
Ready to check your tires? Markovich lays out an easy process:
- Locate the tire’s most worn spot—usually the shallowest groove.
- Grab a quarter, flip it so Washington’s head is upside-down, facing you.
- Slip it into the tread. If his head stays hidden, your tires are still good.
- Seeing the top of his head? Time to shop for new ones.
While you’re at it, glance at your tire pressure too—keeping both in check maximizes safety and performance.
Why This Switch Makes Sense
Switching to a quarter isn’t just about inflation nostalgia—it’s about precision. The extra 2/32 of an inch can mean the difference between gripping a rainy road or sliding off it, especially as tire quality directly impacts handling. Sure, a tread depth gauge offers exact measurements, but for a fast, free check, the quarter wins. Next time you’re assessing tire health, skip the penny and reach for that 25-cent piece instead—it’s a small tweak with big payoffs.
