How do you decide when to buy new tires? Do you wait until you can feel a difference in stopping power? Reduced tread can increase risk of hydroplaning, and decrease stopping distance on wet roads.
One tried and true method is the "penny trick," where you measure tread depth using a penny.
A penny is an accurate measure of depth, however, you may not want to wait to see Lincoln's head emerge from your tread.
In an independent study, researchers found that on a wet road, it takes 10 additional car lengths for a car with 2/32 inch…