How thick is a tire without tread? (2023)

How thick is a tire without tread?

New tires have an average tread depth of 8 to 9 millimeters (10/32 to 11/32 inches). As you drive, the tread will wear down. A tire with a tread depth below 1.6 millimeters (2/32 inches) lacks grip. Braking distance and vehicle control are impaired.

Tires are considered bald when one or more of their grooves reaches 2/32 of an inch deep, compared with about 10/32 of an inch for new tires (tread wear is usually measured in 1/32-inch increments).

WHEN TO REPLACE TIRES. Tread wear indicators appear when the tires only have 2/32 inch or less of tread remaining. Rubber in tires ages over time. This also applies to the spare tire (if available), even if it is never used.

The U.S. Department of Transportation recommends replacing tires when they reach 2/32”, and many states legally require tires to be replaced at this depth. The idea of the penny test is to check whether you've hit the 2/32” threshold.

Bald tires are risky to drive on for two reasons - they're more susceptible to punctures, and they no longer have adequate tread depth to channel water from under the tread. Which means that, when it rains or snows you may lose traction (and control over your vehicle).

Legal regulations

Make sure you check your tread depth a few times a year for your own safety and peace of mind, and remember that the 1.6 mm minimum allowed tread depth is merely a legal limit. For safe driving, tires must be replaced at 3 or 4 mm remaining tread depth.

While tires are classified as bald when one of their grooves measures at 2/32 of an inch, most experts agree that 4/32 is the minimum tire tread depth that should be considered safe. Consumer Reports has studied different tire tread depths and how they handle in different conditions, such as rain and snow.

Schedule an Appointment. You also can measure the tread depth by sticking an upside-down penny into a tread groove. If you can see all of Abraham Lincoln's head, you should replace the tire. When you do this test, you might notice that some tread sections are deeper than 2/32nds of an inch.

The classic method of checking whether your tires are safe is to simply stick a penny upside down in the groove between your tires treads. Make sure that Abe Lincoln's head is pointed straight down towards the rubber.

To meet legal safety standards in the U.S., a tire's tread needs to be at least 2/32” deep. If the tires do not meet the 2/32” standard or are approaching not meeting it, you should replace your tires.

Do I need to replace tires at 4 32?

Put George Washington's head into one of the big grooves. If the top of his head is flush with the tread, you have about 4⁄32 inch of tread left, meaning you have some grip remaining for rainy or snowy conditions. That's the time when you should start shopping for new tires.

He says research carried out by Michelin shows that changing a tyre with 3mm or 4mm of tread remaining – instead of 1.6mm – equates on average to an extra tyre per company car every two years.

Most standard all-season tires start with up to 11/32 of an inch thickness. With additional weight on them and the need for more torque, some truck tires can start with more tread thickness and a more aggressive tread.

If Lincoln's head is covered and no longer visible between the grooves, your tread depth is good. If you can see all of Lincoln's face, it means that the tire tread is 2/32 inches deep or less, and it's time to replace them.

Penny Test for Tire Tread Wear Measurement

Insert a penny into your tire's tread groove with Lincoln's head upside down and facing you. If you can see all of the head, your tire tread depth is less than 2/32 inch and it's time to replace your tires.