Write a Review
American Roadstar
American Roadstar Sport AS 215/45R18
American Roadstar Sport AS 215/45R18
📧 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
Looking for a 215/45R18 tire? The American Roadstar Sport AS is available now at ThreePiece.us with free shipping on every order and Affirm financing at checkout.
What 215/45R18 means
In the size 215/45R18, 215 is the section width in millimeters (8.46 in), 45 is the aspect ratio — the sidewall stands 45% as tall as the tire is wide, or 96.8 mm (3.81 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 25.62 inches, turning roughly 787 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 18 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 89 — a maximum load of 1,279 lbs per tire. The speed symbol W corresponds to a maximum sustained speed of 168 mph.
Specifications
| Size | 215/45R18 |
| Service Description | 89W |
| Load Index | 89 |
| Speed Rating | W |
| Section Width (mm) | 215 |
| Aspect Ratio | 45 |
| Overall Diameter (in) | 18 |
| Treadwear | 500 |
| Traction Grade | A |
| Temperature Grade | A |
| UTQG | 500 A A |
Frequently asked questions
What are the treadwear and warranty ratings on the American Roadstar Sport AS?
This tire carries a treadwear grade of 500, traction grade A, temperature grade A under UTQG.
Will 215/45R18 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 215/45R18, this tire matches your vehicle's fitment. If you're changing sizes, compare overall diameter to keep your speedometer and clearances right. See every 215/45R18 tire in stock to compare options.
What does 89W mean on the American Roadstar Sport AS?
89W breaks down as load index 89 — rated for 1,279 lbs per tire — with a W speed rating, good for a maximum sustained 168 mph.
Keep shopping
Shop all 215/45R18 tires, see every American Roadstar Sport AS size, or view all tires at ThreePiece.us.
- BRAND:
- American Roadstar
- Model:
- Sport AS
- Size:
- 215/45R18
- Aspect Ratio:
- 45
- Load Index:
- 89
- Load Range:
- N/A
- Section Width:
- 215
- Service Description:
- 89W
- Speed Index:
- W
- Temperature:
- A
- Tire Rim Diameter:
- 18
- Tire Type:
- N/A
- Traction:
- A
- Tread Wear:
- 500
- Max Load (LB):
- 1278.66
- UQTG:
- 500 A A
- Side Wall:
- N/A
- 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