Before a long trip, you do the penny test on your tires. You put the penny head-first into the groove where the tread looks lowest, and you can see all of Lincoln's head. What does this tell you?

Correct answer: The tread is too worn, so the tire will grip poorly on wet or slippery roads.

Why

Tread grooves let the tire keep its grip when the road is wet or slippery, so worn tread increases the risk of a skid. Check your tires for wear and damage once a month and before a long trip. Also check the pressure with a gauge, and use the psi shown in the owner's manual or on the driver's side door jamb.

Verified against Official Nevada Driver Handbook · Tire safety · p. 27