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Gt Radial
GT Radial Champiro HPY 255/55ZR18XL 109Y - B342
GT Radial Champiro HPY 255/55ZR18XL 109Y - B342
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The GT Radial Champiro HPY in 255/55R18 ships free from ThreePiece.us, with Affirm financing available at checkout and fast delivery from a nationwide warehouse network.
What 255/55R18 means
In the size 255/55R18, 255 is the section width in millimeters (10.04 in), 55 is the aspect ratio — the sidewall stands 55% as tall as the tire is wide, or 140.2 mm (5.52 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 29.04 inches, turning roughly 694 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 109 — a maximum load of 2,271 lbs per tire. The speed symbol Y corresponds to a maximum sustained speed of 186 mph.
Specifications
| Size | 255/55ZR18XL |
| Tire Type | Summer |
| Service Description | 109Y |
| Load Index | 109 |
| Speed Rating | Y |
| Load Range | XL |
| Section Width (mm) | 255 |
| Aspect Ratio | 55 |
| Overall Diameter (in) | 29 |
| Tread Depth (/32") | 10 |
| Treadwear | 300 |
| Traction Grade | AA |
| Temperature Grade | A |
| UTQG | 300AAA |
Frequently asked questions
What does 109Y mean on the GT Radial Champiro HPY?
109Y breaks down as load index 109 — rated for 2,271 lbs per tire — with a Y speed rating, good for a maximum sustained 186 mph.
What kind of tire is the GT Radial Champiro HPY?
The GT Radial Champiro HPY in 255/55R18 is a summer tire.
What are the treadwear and warranty ratings on the GT Radial Champiro HPY?
This tire carries a treadwear grade of 300, traction grade AA, temperature grade A under UTQG.
Keep shopping
Shop all 255/55R18 tires, browse GT Radial tires, see every GT Radial Champiro HPY size, or view all tires at ThreePiece.us.
- BRAND:
- GT Radial
- Model:
- Champiro HPY
- Size:
- 255/55ZR18XL
- Aspect Ratio:
- 55
- Load Index:
- 109
- Load Range:
- XL
- Section Width:
- 255
- Service Description:
- 109Y
- Speed Index:
- Y
- Temperature:
- A
- Tire Rim Diameter:
- 29
- Tire Type:
- Summer
- Traction:
- AA
- Tread Wear:
- 300
- Tread Depth:
- 10
- UQTG:
- 300AAA
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