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AMP
AMP Terrain Pro A/T LT285/55R20
AMP Terrain Pro A/T LT285/55R20
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The AMP Terrain Pro A/T in 285/55R20 ships free from ThreePiece.us, with Affirm financing available at checkout and fast delivery from a nationwide warehouse network.
What 285/55R20 means
In the size 285/55R20, 285 is the section width in millimeters (11.22 in), 55 is the aspect ratio — the sidewall stands 55% as tall as the tire is wide, or 156.8 mm (6.17 in) — R denotes radial construction, and 20 is the wheel diameter in inches. That works out to an overall diameter of about 32.34 inches, turning roughly 624 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 122 — a maximum load of 3,307 lbs per tire, or 119 (2,998 lbs) per tire when mounted as duals. The speed symbol S corresponds to a maximum sustained speed of 112 mph.
Load Range E corresponds to a 10-ply rating.
Specifications
| Size | LT285/55R20 |
| Tire Type | All Terrain |
| Service Description | 122/119S |
| Load Index | 122/119 |
| Speed Rating | S |
| Load Range | E |
| Section Width (mm) | 285 |
| Aspect Ratio | 55 |
| Overall Diameter (in) | 32.36 |
| Tread Depth (/32") | 15.75 |
| Traction Grade | A |
| Warranty | 60K |
Frequently asked questions
What does 122/119S mean on the AMP Terrain Pro A/T?
122/119S breaks down as load index 122 — rated for 3,307 lbs per tire (119, or 2,998 lbs, in dual fitment) — with an S speed rating, good for a maximum sustained 112 mph.
What kind of tire is the AMP Terrain Pro A/T?
The AMP Terrain Pro A/T in 285/55R20 is a all terrain tire.
What warranty does the AMP Terrain Pro A/T carry?
The manufacturer's warranty on this tire is 60K.
Keep shopping
Shop all 285/55R20 tires, see every AMP Terrain Pro A/T size, explore all terrain tires, or view all tires at ThreePiece.us.
- BRAND:
- AMP
- Model:
- Terrain Pro A/T
- Size:
- LT285/55R20
- Aspect Ratio:
- 55
- Load Index:
- 122/119
- Load Range:
- E
- Section Width:
- 285
- Service Description:
- 122/119S
- Speed Index:
- S
- Inflation Pressure:
- 80 PSI
- Tire Rim Diameter:
- 32.36
- Tire Type:
- All Terrain
- Traction:
- A
- Tread Wear:
- N/A
- Tread Depth:
- 15.75
- Tread Construction:
- 2P+2S+1N
- Warranty:
- 60K
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