Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/25-20 | 255/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.41 (645.5) | 26.03 (661.2) | 0.62 (15.7) 2.4% |
| Width inches (mm) | 10.83 (275) | 10.04 (255) | -0.79 (-20) -7.3% |
| Circum. inches (mm) | 79.84 (2027.9) | 81.78 (2077.22) | 1.94 (49.32) 2.4% |
| Sidewall Height inches (mm) | 2.71 (68.75) | 4.02 (102) | 1.31 (33.25) 48.4% |
| Revolutions per mile (km) | 793.6 (493.12) | 774.76 (481.41) | -18.84 (-11.71) -2.4% |
255/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.49 mph (32.97 km/h) |
| 25 mph (40.23 km/h) | 25.61 mph (41.21 km/h) |
| 30 mph (48.28 km/h) | 30.73 mph (49.45 km/h) |
| 35 mph (56.33 km/h) | 35.85 mph (57.7 km/h) |
| 40 mph (64.37 km/h) | 40.97 mph (65.94 km/h) |
| 45 mph (72.42 km/h) | 46.09 mph (74.18 km/h) |
| 50 mph (80.47 km/h) | 51.22 mph (82.42 km/h) |
| 55 mph (88.51 km/h) | 56.34 mph (90.67 km/h) |
| 60 mph (96.56 km/h) | 61.46 mph (98.91 km/h) |
| 65 mph (104.61 km/h) | 66.58 mph (107.15 km/h) |
| 70 mph (112.65 km/h) | 71.7 mph (115.39 km/h) |
| 75 mph (120.7 km/h) | 76.82 mph (123.64 km/h) |
| 80 mph (128.75 km/h) | 81.95 mph (131.88 km/h) |
| 85 mph (136.79 km/h) | 87.07 mph (140.12 km/h) |
| 90 mph (144.84 km/h) | 92.19 mph (148.36 km/h) |
| 95 mph (152.89 km/h) | 97.31 mph (156.61 km/h) |
| 100 mph (160.93 km/h) | 102.43 mph (164.85 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1972 | 2290 | 2467 | 2576 | 2693 | 2777 | 2869 | 2978 | 3129 | 3280 | 3448 | 3582 | 3826 | 4094 | 4304 | 4438 | 4514 | 4791 | 5177 | 6016 |
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