Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/30-20 | 255/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.44 (697) | 28.03 (712) | 0.59 (15) 2.2% |
| Width inches (mm) | 12.4 (315) | 10.04 (255) | -2.36 (-60) -19% |
| Circum. inches (mm) | 86.21 (2189.69) | 88.06 (2236.81) | 1.86 (47.12) 2.2% |
| Sidewall Height inches (mm) | 3.72 (94.5) | 4.02 (102) | 0.3 (7.5) 7.9% |
| Revolutions per mile (km) | 734.96 (456.68) | 719.48 (447.06) | -15.48 (-9.62) -2.1% |
255/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.43 mph (32.88 km/h) |
| 25 mph (40.23 km/h) | 25.54 mph (41.1 km/h) |
| 30 mph (48.28 km/h) | 30.65 mph (49.32 km/h) |
| 35 mph (56.33 km/h) | 35.75 mph (57.54 km/h) |
| 40 mph (64.37 km/h) | 40.86 mph (65.76 km/h) |
| 45 mph (72.42 km/h) | 45.97 mph (73.98 km/h) |
| 50 mph (80.47 km/h) | 51.08 mph (82.2 km/h) |
| 55 mph (88.51 km/h) | 56.18 mph (90.42 km/h) |
| 60 mph (96.56 km/h) | 61.29 mph (98.64 km/h) |
| 65 mph (104.61 km/h) | 66.4 mph (106.86 km/h) |
| 70 mph (112.65 km/h) | 71.51 mph (115.08 km/h) |
| 75 mph (120.7 km/h) | 76.61 mph (123.3 km/h) |
| 80 mph (128.75 km/h) | 81.72 mph (131.52 km/h) |
| 85 mph (136.79 km/h) | 86.83 mph (139.74 km/h) |
| 90 mph (144.84 km/h) | 91.94 mph (147.96 km/h) |
| 95 mph (152.89 km/h) | 97.04 mph (156.18 km/h) |
| 100 mph (160.93 km/h) | 102.15 mph (164.4 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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