Cooper Tires COO Discoverer AT3 4S 275/65R18

Looking for a 275/65R18 all terrain tire? The Cooper Tires Discoverer AT3 4S is available now at ThreePiece.us with free shipping on every order and Affirm financing at checkout.

What 275/65R18 means

In the size 275/65R18, 275 is the section width in millimeters (10.83 in), 65 is the aspect ratio — the sidewall stands 65% as tall as the tire is wide, or 178.8 mm (7.04 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 32.07 inches, turning roughly 629 revolutions per mile. Overall diameter is what matters for speedometer accuracy and clearance when you change sizes, so compare it — not just the width — against your current tire.

The service description on this tire decodes to a load index of 116 — a maximum load of 2,756 lbs per tire. The speed symbol T corresponds to a maximum sustained speed of 118 mph.

Specifications

Frequently asked questions

What kind of tire is the Cooper Tires Discoverer AT3 4S?

The Cooper Tires Discoverer AT3 4S in 275/65R18 is a all terrain tire.

What are the treadwear and warranty ratings on the Cooper Tires Discoverer AT3 4S?

This tire carries a treadwear grade of 620, traction grade A, temperature grade B under UTQG. The manufacturer's warranty is 65K.

What does 116T mean on the Cooper Tires Discoverer AT3 4S?

116T breaks down as load index 116 — rated for 2,756 lbs per tire — with a T speed rating, good for a maximum sustained 118 mph.

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