Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/30-20 | 285/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.44 (697) | 26.73 (679) | -0.71 (-18) -2.6% |
| Width inches (mm) | 12.4 (315) | 11.22 (285) | -1.18 (-30) -9.5% |
| Circum. inches (mm) | 86.21 (2189.69) | 83.98 (2133.14) | -2.23 (-56.55) -2.6% |
| Sidewall Height inches (mm) | 3.72 (94.5) | 3.37 (85.5) | -0.35 (-9) -9.5% |
| Revolutions per mile (km) | 734.96 (456.68) | 754.45 (468.79) | 19.48 (12.11) 2.7% |
285/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.48 mph (31.36 km/h) |
| 25 mph (40.23 km/h) | 24.35 mph (39.19 km/h) |
| 30 mph (48.28 km/h) | 29.23 mph (47.03 km/h) |
| 35 mph (56.33 km/h) | 34.1 mph (54.87 km/h) |
| 40 mph (64.37 km/h) | 38.97 mph (62.71 km/h) |
| 45 mph (72.42 km/h) | 43.84 mph (70.55 km/h) |
| 50 mph (80.47 km/h) | 48.71 mph (78.39 km/h) |
| 55 mph (88.51 km/h) | 53.58 mph (86.23 km/h) |
| 60 mph (96.56 km/h) | 58.45 mph (94.07 km/h) |
| 65 mph (104.61 km/h) | 63.32 mph (101.91 km/h) |
| 70 mph (112.65 km/h) | 68.19 mph (109.75 km/h) |
| 75 mph (120.7 km/h) | 73.06 mph (117.58 km/h) |
| 80 mph (128.75 km/h) | 77.93 mph (125.42 km/h) |
| 85 mph (136.79 km/h) | 82.8 mph (133.26 km/h) |
| 90 mph (144.84 km/h) | 87.68 mph (141.1 km/h) |
| 95 mph (152.89 km/h) | 92.55 mph (148.94 km/h) |
| 100 mph (160.93 km/h) | 97.42 mph (156.78 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1920 | 2230 | 2402 | 2508 | 2623 | 2704 | 2794 | 2900 | 3047 | 3194 | 3358 | 3489 | 3725 | 3987 | 4191 | 4322 | 4395 | 4665 | 5041 | 5858 |
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