Write a Review
Ironman
Ironman IRON All Country HT 255/55R18XL
Ironman IRON All Country HT 255/55R18XL
📧 Get Fitment Help
Verify parts fit & get product recommendations
Lease-to-own for as low as
/week
Get Started
Guaranteed to Fit — confirm your size with the fitment checker on this page
Price Match Guarantee Learn More
Free Mount & Balance
Free Shipping
OUT OF STOCK 
📧 Get Fitment Help
Verify parts fit & get product recommendations
The Ironman All Country HT 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 V corresponds to a maximum sustained speed of 149 mph.
Specifications
| Size | 255/55R18XL |
| Tire Type | Highway |
| Service Description | 109V |
| Load Index | 109 |
| Speed Rating | V |
| Load Range | XL |
| Section Width (mm) | 255 |
| Aspect Ratio | 55 |
| Overall Diameter (in) | 29.06 |
| Tread Depth (/32") | 10.5 |
| Treadwear | 500 |
| Traction Grade | A |
| Temperature Grade | B |
| UTQG | 500AB |
Frequently asked questions
What does 109V mean on the Ironman All Country HT?
109V breaks down as load index 109 — rated for 2,271 lbs per tire — with a V speed rating, good for a maximum sustained 149 mph.
What kind of tire is the Ironman All Country HT?
The Ironman All Country HT in 255/55R18 is a highway tire.
What are the treadwear and warranty ratings on the Ironman All Country HT?
This tire carries a treadwear grade of 500, traction grade A, temperature grade B under UTQG.
Keep shopping
Shop all 255/55R18 tires, see every Ironman All Country HT size, or view all tires at ThreePiece.us.
- BRAND:
- Ironman
- Model:
- IRON All Country HT
- Size:
- 255/55R18XL
- Aspect Ratio:
- 55
- Load Index:
- 109
- Load Range:
- XL
- Section Width:
- 255
- Service Description:
- 109V
- Speed Index:
- V
- Temperature:
- B
- Tire Rim Diameter:
- 29.06
- Tire Type:
- Highway
- Traction:
- A
- Tread Wear:
- 500
- Tread Depth:
- 10.5
- UQTG:
- 500AB
- Warranty:
- N/A
PRODUCT REVIEWS (0)
Overall Rankings
Have you tried this product?
WRITE A REVIEWNo reviews for this product yet. Be the first to write a review!
Write a Review