Worn tires can be dangerous, especially in wet and winter weather. New tests from Consumer Reports show that even before your tires are completely worn out, their performance and your safety are compromised.

The tire that has full tread has lots of biting edges for winter traction and channels dissipate water. As a tire wears, a lot of those biting edges go away, and the channels don’t have any depth so the water has nowhere to go.

Consumer Reports’ newest tests show that even before a tire is completely worn, vehicles can take longer to stop on wet pavement. Cornering is also compromised. The tires just don’t have the grip they had when they were new.

Consumer Reports has developed an easy way for you to check your tires. If you insert a penny upside down into the tread and you can see all of Lincoln’s hair, that tire is legally worn out.

Consumer Reports says an even better test is the quarter test. By doing the same thing and seeing all of George Washington’s hair, you know that your tire has potentially compromised its safety and it gives you time to shop for a replacement before you absolutely need it.