Accelera Iota ST68 225/55R18

Looking for a 225/55R18 tire? The Accelera Iota ST68 is available now at ThreePiece.us with free shipping on every order and Affirm financing at checkout.

What 225/55R18 means

In the size 225/55R18, 225 is the section width in millimeters (8.86 in), 55 is the aspect ratio — the sidewall stands 55% as tall as the tire is wide, or 123.8 mm (4.87 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 27.74 inches, turning roughly 727 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 103 — a maximum load of 1,929 lbs per tire. The speed symbol H corresponds to a maximum sustained speed of 130 mph.

Specifications

Frequently asked questions

Will 225/55R18 tires fit my vehicle?

Check the size molded into your current tire's sidewall or the tire placard inside the driver's door jamb — if it reads 225/55R18, this tire matches your vehicle's fitment. If you're changing sizes, compare overall diameter to keep your speedometer and clearances right. See every 225/55R18 tire in stock to compare options.

How fast does this tire ship?

Every order at ThreePiece.us ships free, with fast delivery from a nationwide warehouse network. Affirm financing is available at checkout.

What does 103H mean on the Accelera Iota ST68?

103H breaks down as load index 103 — rated for 1,929 lbs per tire — with an H speed rating, good for a maximum sustained 130 mph.

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