Used tire grading checklist

A practical A/B/C grading system for used tires covering tread, age, repairs and cosmetic condition, plus the full list of reasons to refuse a tire outright.

The caveat first

A grade written on a tire is shorthand. It isn't a promise. "B" tells the next person on the rack roughly what to expect, not that the tire is flawless. Write it honestly or don't write it at all. A customer who buys a B-grade tire expecting A-grade performance is a return waiting to happen, and worse, a complaint that sticks to the shop's name long after the tire's gone.

What A, B, and C mean at our shop

• Grade A: 8/32" or deeper, no repairs, no sidewall damage, under 6 years old by the DOT code. Looks and performs close to new.
• Grade B: 5/32" to 7/32", at most one repair in the tread itself (never the shoulder or sidewall), no cracking visible, 6 to 8 years old. A solid daily-driver tire.
• Grade C: 4/32" to 5/32", or minor cosmetic wear that's purely cosmetic, still within the shop's sell line. Priced accordingly and sold with a clear explanation of what the customer's getting.

Anything below a C on any of those measures doesn't get graded. It gets refused.

Cosmetic condition, and why it's the weakest grading factor

Scuffed sidewalls, faded lettering, or a little curb rash on the shoulder don't affect how a tire performs. They affect how it looks in a photo and how confident a customer feels buying it. We let cosmetic issues nudge a tire from B to C, never further, and never on their own. A tire that grades A on tread, age, and repairs doesn't drop to C just because it looks dusty from sitting outside. Clean it up first. Half the "cosmetic problem" tires just need a rag and some tire shine before they photograph fine.

The refusal list

Some tires never make it to a grade because they don't get sold, full stop. Any one of these is an automatic refusal:

• Exposed cord or belt material anywhere on the tire
• A bulge or bubble in the sidewall
• Bead damage that won't seat cleanly
• A plug or patch in the shoulder or sidewall, rather than the tread
• Cracking in the grooves, sometimes called weather checking
• More than one repair anywhere in the tire
• A single repair larger than 1/4 inch
• Uneven wear that drops below 2/32" anywhere across the tread
• A DOT date over 10 years old
• A tire that doesn't match its mate closely enough to sell as a pair

If a tire hits any one of these, it doesn't matter how good the rest of it looks. It goes to disposal, not the rack.

Writing the grade down twice

The grade goes on the tire itself first, in chalk or marker where the next person can see it without hunting for it. Rack B2, grade B, 6/32", written right on the sidewall. Then it goes in the record: size, brand, DOT, tread depth at intake, grade, and source, all in one line so nobody has to guess later what a "B" meant on a tire that came in three months back.

Two places, same information. It sounds redundant until the day a customer asks why a tire they bought two months ago is already worn thin, and you can pull up exactly what it measured on the way in.

For the tread numbers behind these grades, see our tread depth chart, and to check a tire's age from its DOT code before you grade it, see how to read a DOT date code.

Pairs and sets

Don't sell a pair with more than 2/32" of difference between the two tires. On front-wheel-drive cars, put the deeper-tread pair on the rear axle, not the front. That's standard practice most shops and manufacturers recommend. Directional tires have an arrow molded into the sidewall showing which way they should rotate. Asymmetric tires say OUTSIDE on the side that faces out. Get either one backward and it's a comeback, not a sale.

DuroBay tracks grade, tread, and source on every used tire automatically. Its pair finder groups singles within 1/32" into sellable sets on its own, so nobody's matching tread depths by eye across forty tires in the used rack.

Training a new hire on grading

Don't hand someone the letter scale and walk away. Grade five or six tires together first, out loud, so they hear the reasoning behind each call, not just the result. Show them a borderline B-versus-C tire and explain which way it broke and why. After that, have them grade a small batch alone and check their work before it hits the rack. Most people get consistent within a week if the reasoning gets explained every time, not just the grade itself.