Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/45-20 | 255/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.33 (719.5) | 28.03 (712) | -0.3 (-7.5) -1% |
| Width inches (mm) | 9.25 (235) | 10.04 (255) | 0.79 (20) 8.5% |
| Circum. inches (mm) | 88.99 (2260.38) | 88.06 (2236.81) | -0.93 (-23.56) -1% |
| Sidewall Height inches (mm) | 4.16 (105.75) | 4.02 (102) | -0.15 (-3.75) -3.5% |
| Revolutions per mile (km) | 711.98 (442.4) | 719.48 (447.06) | 7.5 (4.66) 1.1% |
255/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.79 mph (31.85 km/h) |
| 25 mph (40.23 km/h) | 24.74 mph (39.81 km/h) |
| 30 mph (48.28 km/h) | 29.69 mph (47.78 km/h) |
| 35 mph (56.33 km/h) | 34.64 mph (55.74 km/h) |
| 40 mph (64.37 km/h) | 39.58 mph (63.7 km/h) |
| 45 mph (72.42 km/h) | 44.53 mph (71.67 km/h) |
| 50 mph (80.47 km/h) | 49.48 mph (79.63 km/h) |
| 55 mph (88.51 km/h) | 54.43 mph (87.59 km/h) |
| 60 mph (96.56 km/h) | 59.37 mph (95.55 km/h) |
| 65 mph (104.61 km/h) | 64.32 mph (103.52 km/h) |
| 70 mph (112.65 km/h) | 69.27 mph (111.48 km/h) |
| 75 mph (120.7 km/h) | 74.22 mph (119.44 km/h) |
| 80 mph (128.75 km/h) | 79.17 mph (127.41 km/h) |
| 85 mph (136.79 km/h) | 84.11 mph (135.37 km/h) |
| 90 mph (144.84 km/h) | 89.06 mph (143.33 km/h) |
| 95 mph (152.89 km/h) | 94.01 mph (151.29 km/h) |
| 100 mph (160.93 km/h) | 98.96 mph (159.26 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1831 | 2127 | 2291 | 2392 | 2501 | 2579 | 2665 | 2766 | 2906 | 3046 | 3202 | 3327 | 3553 | 3802 | 3997 | 4122 | 4192 | 4449 | 4807 | 5586 |
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