Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/55-21 | 255/55-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.91 (835.9) | 29.04 (737.7) | -3.87 (-98.2) -11.7% |
| Width inches (mm) | 10.83 (275) | 10.04 (255) | -0.79 (-20) -7.3% |
| Circum. inches (mm) | 103.39 (2626.06) | 91.24 (2317.55) | -12.15 (-308.5) -11.7% |
| Sidewall Height inches (mm) | 5.95 (151.25) | 5.52 (140.25) | -0.43 (-11) -7.3% |
| Revolutions per mile (km) | 612.84 (380.8) | 694.42 (431.49) | 81.58 (50.69) 13.3% |
255/55-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.65 mph (28.41 km/h) |
| 25 mph (40.23 km/h) | 22.06 mph (35.51 km/h) |
| 30 mph (48.28 km/h) | 26.48 mph (42.61 km/h) |
| 35 mph (56.33 km/h) | 30.89 mph (49.71 km/h) |
| 40 mph (64.37 km/h) | 35.3 mph (56.81 km/h) |
| 45 mph (72.42 km/h) | 39.71 mph (63.91 km/h) |
| 50 mph (80.47 km/h) | 44.13 mph (71.01 km/h) |
| 55 mph (88.51 km/h) | 48.54 mph (78.12 km/h) |
| 60 mph (96.56 km/h) | 52.95 mph (85.22 km/h) |
| 65 mph (104.61 km/h) | 57.36 mph (92.32 km/h) |
| 70 mph (112.65 km/h) | 61.78 mph (99.42 km/h) |
| 75 mph (120.7 km/h) | 66.19 mph (106.52 km/h) |
| 80 mph (128.75 km/h) | 70.6 mph (113.62 km/h) |
| 85 mph (136.79 km/h) | 75.01 mph (120.72 km/h) |
| 90 mph (144.84 km/h) | 79.43 mph (127.83 km/h) |
| 95 mph (152.89 km/h) | 83.84 mph (134.93 km/h) |
| 100 mph (160.93 km/h) | 88.25 mph (142.03 km/h) |
| 2.35 | 2.73 | 2.94 | 3.07 | 3.21 | 3.31 | 3.42 | 3.55 | 3.73 | 3.91 | 4.11 | 4.27 | 4.56 | 4.88 | 5.13 | 5.29 | 5.38 | 5.71 | 6.17 | 7.17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1767 | 2053 | 2211 | 2309 | 2414 | 2489 | 2572 | 2670 | 2805 | 2940 | 3091 | 3211 | 3429 | 3670 | 3858 | 3978 | 4046 | 4294 | 4640 | 5392 |
Better Fuel Economy Factory Ratios Increased Power
