Fleet Tire Safety Checks: Pressure, Tread and Age

Tires are one of the few safety items a driver can check in a couple of minutes with a gauge and a coin. NHTSA reports that in 2024, a total of 511 people died on the road in tire-related crashes (NHTSA: Tires). For a fleet, the job is to turn NHTSA’s advice into a routine every driver follows.

How do you check tire pressure correctly?

• Check the pressure of all tires, including the spare, at least once a month when the tires are “cold,” which NHTSA explains means the vehicle hasn’t been driven for at least three hours.
• Use the pressure on the Tire and Loading Information Label on the driver’s side door edge, or in the owner’s manual. NHTSA stresses that the correct pressure is what the vehicle manufacturer has listed, not what is listed on the tire itself.
• Keep a tire pressure gauge in each vehicle so drivers don’t have to borrow one.

Isn’t the tire pressure warning light enough?

No. NHTSA says passenger cars, light trucks and vans from model year 2008 or newer are required to have a tire pressure monitoring system (TPMS), but the warning only comes on when a tire is significantly underinflated. In NHTSA’s words, “The TPMS is not intended to be a substitute for regular tire maintenance.”

When should a tire be replaced for tread?

NHTSA says tires are not safe and should be replaced when the tread is worn down to 2/32 of an inch, and suggests checking tread at least once a month when you check pressure. Two quick checks:

• Treadwear indicators: raised sections that run between the tread. When the tread is level with them, it’s time to replace the tire.
• Penny test: place a penny in the tread with Lincoln’s head upside down and facing you. If you can see the top of his head, replace the tire.

How often should tires be rotated?

Follow the owner’s manual. NHTSA says that, if recommended by the vehicle manufacturer, tires should be rotated every 5,000 to 8,000 miles, or sooner if uneven wear appears.

How old is too old?

NHTSA says that as tires age, they are more prone to failure, and that some vehicle and tire manufacturers recommend replacing tires that are six to 10 years old, regardless of treadwear. To find the age, look on the sidewall for the DOT Tire Identification Number (TIN):

The last four digits of the TIN indicate the week and year the tire was made.

For example, NHTSA says a TIN ending in 0308 means the tire was made in the third week of 2008. NHTSA also warns that owners of 15-passenger vans, vehicles they don’t drive regularly, or vehicles with low annual mileage could be at risk from aging tires, which matters for the spare van that only runs in the busy season.

Anything special for passenger vans?

For 15-passenger vans, NHTSA’s advice is to “Make certain the van has appropriately sized and load-rated tires that are properly inflated before every trip.”

A monthly tire routine for drivers

• First workday of the month, before the first trip: cold pressure check on every tire and the spare.
• Tread check with the indicators or a penny.
• Read and note the TIN date on any tire that looks old or has been on a little-used vehicle.
• Write the results in the vehicle’s inspection record (see our fleet checklist), and check tire recalls with NHTSA (see recall checks).

What should the tire record show?

A tire check only helps if someone can see it later. For each vehicle, each month:

• the date and who checked;
• the cold pressure found and the pressure set, for each tire and the spare;
• the tread result (indicators or penny test) and any tire close to 2/32 of an inch;
• any tire with an old TIN date, and when it’s planned for replacement.

If a vehicle sits for weeks between jobs, check it before it goes back on the road, not just on the monthly date.