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Accelera
Accelera PHI 255/40R18
Accelera PHI 255/40R18
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Shop the Accelera PHI 255/40R18 at ThreePiece.us — free shipping on every order, Affirm financing available, and fast delivery nationwide.
What 255/40R18 means
In the size 255/40R18, 255 is the section width in millimeters (10.04 in), 40 is the aspect ratio — the sidewall stands 40% as tall as the tire is wide, or 102.0 mm (4.02 in) — R denotes radial construction, and 18 is the wheel diameter in inches. That works out to an overall diameter of about 26.03 inches, turning roughly 775 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 99 — a maximum load of 1,709 lbs per tire. The speed symbol Y corresponds to a maximum sustained speed of 186 mph.
Specifications
| Size | 255/40R18 |
| Service Description | 99Y |
| Load Index | 99 |
| Speed Rating | Y |
| Load Range | XL |
| Section Width (mm) | 255 |
| Aspect Ratio | 40 |
| Temperature Grade | ATIRE RIM DIAMETER=18TIRE TYPE=TRACTION=AATREAD WEAR=300TREAD DEPTH=UQTG=300 AA AWARRANTY= |
Frequently asked questions
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 99Y mean on the Accelera PHI?
99Y breaks down as load index 99 — rated for 1,709 lbs per tire — with a Y speed rating, good for a maximum sustained 186 mph.
Will 255/40R18 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 255/40R18, this tire matches your vehicle's fitment. If you're changing sizes, compare overall diameter to keep your speedometer and clearances right. See every 255/40R18 tire in stock to compare options.
Keep shopping
Shop all 255/40R18 tires, browse Accelera tires, see every Accelera PHI size, or view all tires at ThreePiece.us.
- BRAND:
- Accelera
- MODEL:
- PHI
- SIZE:
- 255/40R18
- ASPECT RATIO:
- 40
- LOAD INDEX:
- 99
- LOAD RANGE:
- XL
- SECTION WIDTH:
- 255
- SERVICE DESCRIPTION:
- 99Y
- SPEED INDEX:
- Y
- TEMPERATURE:
- ATIRE RIM DIAMETER=18TIRE TYPE=TRACTION=AATREAD WEAR=300TREAD DEPTH=UQTG=300 AA AWARRANTY=
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