Quarters are safer than pennies when it comes to checking your tires, according to new tests conducted by The Tire Rack, an independent tire tester. For decades the tire industry has taught drivers to use the so-called Penny Test as a simple way to tell when tires were worn out. But experts at The Tire Rack say that popular lesson is outdated, compromises safety, and should give way to the Quarter Test. In the old Penny Test, seeing the top of Lincoln's head while holding a penny upside down in a tire tread groove indicated a tread depth of 2/32-inch (1.6mm) or less, and that the tire needed replacing. Not only were braking distances significantly reduced with the Quarter Test, overall grip noticeably improved. Footage comparing Penny- and Quarter-Tested tires is available online at tirerack.com/baldtiredangers .