Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/55-20 | 235/55-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.18 (766.5) | 28.18 (715.7) | -2 (-50.8) -6.6% |
| Width inches (mm) | 9.25 (235) | 9.25 (235) | 0 (0) 0% |
| Circum. inches (mm) | 94.8 (2408.03) | 88.52 (2248.44) | -6.28 (-159.59) -6.6% |
| Sidewall Height inches (mm) | 5.09 (129.25) | 5.09 (129.25) | 0 (0) 0% |
| Revolutions per mile (km) | 668.32 (415.28) | 715.76 (444.75) | 47.44 (29.48) 7.1% |
235/55-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.67 mph (30.05 km/h) |
| 25 mph (40.23 km/h) | 23.34 mph (37.57 km/h) |
| 30 mph (48.28 km/h) | 28.01 mph (45.08 km/h) |
| 35 mph (56.33 km/h) | 32.68 mph (52.59 km/h) |
| 40 mph (64.37 km/h) | 37.35 mph (60.11 km/h) |
| 45 mph (72.42 km/h) | 42.02 mph (67.62 km/h) |
| 50 mph (80.47 km/h) | 46.69 mph (75.13 km/h) |
| 55 mph (88.51 km/h) | 51.35 mph (82.65 km/h) |
| 60 mph (96.56 km/h) | 56.02 mph (90.16 km/h) |
| 65 mph (104.61 km/h) | 60.69 mph (97.67 km/h) |
| 70 mph (112.65 km/h) | 65.36 mph (105.19 km/h) |
| 75 mph (120.7 km/h) | 70.03 mph (112.7 km/h) |
| 80 mph (128.75 km/h) | 74.7 mph (120.21 km/h) |
| 85 mph (136.79 km/h) | 79.37 mph (127.73 km/h) |
| 90 mph (144.84 km/h) | 84.04 mph (135.24 km/h) |
| 95 mph (152.89 km/h) | 88.7 mph (142.76 km/h) |
| 100 mph (160.93 km/h) | 93.37 mph (150.27 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1821 | 2116 | 2279 | 2380 | 2488 | 2566 | 2651 | 2752 | 2891 | 3031 | 3186 | 3310 | 3534 | 3782 | 3976 | 4100 | 4170 | 4426 | 4782 | 5557 |
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