Cooper Discoverer Rugged Trek 285/75R18 129/126Q - 170274046

Looking for a 285/75R18 all season tire? The Cooper Discoverer Rugged Trek is available now at ThreePiece.us with free shipping on every order and Affirm financing at checkout.

What 285/75R18 means

In the size 285/75R18, 285 is the section width in millimeters (11.22 in), 75 is the aspect ratio — the sidewall stands 75% as tall as the tire is wide, or 213.8 mm (8.42 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 34.83 inches, turning roughly 579 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 manufacturer lists the overall diameter of this specific tire as 35.08 inches — when clearance is tight, go by the published figure rather than the nominal size math.

The service description on this tire decodes to a load index of 129 — a maximum load of 4,079 lbs per tire, or 126 (3,748 lbs) per tire when mounted as duals. The speed symbol Q corresponds to a maximum sustained speed of 99 mph.

Load Range E corresponds to a 10-ply rating.

Specifications

Frequently asked questions

What kind of tire is the Cooper Discoverer Rugged Trek?

The Cooper Discoverer Rugged Trek in 285/75R18 is a all season tire.

What warranty does the Cooper Discoverer Rugged Trek carry?

The manufacturer's warranty on this tire is 55K.

What does 129/126Q mean on the Cooper Discoverer Rugged Trek?

129/126Q breaks down as load index 129 — rated for 4,079 lbs per tire (126, or 3,748 lbs, in dual fitment) — with a Q speed rating, good for a maximum sustained 99 mph.

Keep shopping

Browse Cooper tires, see every Cooper Discoverer Rugged Trek size, or view all tires at ThreePiece.us.