Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/30-20 | 255/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.55 (649) | 26.02 (661) | 0.47 (12) 1.8% |
| Width inches (mm) | 9.25 (235) | 10.04 (255) | 0.79 (20) 8.5% |
| Circum. inches (mm) | 80.27 (2038.89) | 81.76 (2076.59) | 1.48 (37.7) 1.8% |
| Sidewall Height inches (mm) | 2.78 (70.5) | 3.01 (76.5) | 0.24 (6) 8.5% |
| Revolutions per mile (km) | 789.32 (490.46) | 774.99 (481.56) | -14.33 (-8.9) -1.8% |
255/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.37 mph (32.78 km/h) |
| 25 mph (40.23 km/h) | 25.46 mph (40.98 km/h) |
| 30 mph (48.28 km/h) | 30.55 mph (49.17 km/h) |
| 35 mph (56.33 km/h) | 35.65 mph (57.37 km/h) |
| 40 mph (64.37 km/h) | 40.74 mph (65.56 km/h) |
| 45 mph (72.42 km/h) | 45.83 mph (73.76 km/h) |
| 50 mph (80.47 km/h) | 50.92 mph (81.96 km/h) |
| 55 mph (88.51 km/h) | 56.02 mph (90.15 km/h) |
| 60 mph (96.56 km/h) | 61.11 mph (98.35 km/h) |
| 65 mph (104.61 km/h) | 66.2 mph (106.54 km/h) |
| 70 mph (112.65 km/h) | 71.29 mph (114.74 km/h) |
| 75 mph (120.7 km/h) | 76.39 mph (122.93 km/h) |
| 80 mph (128.75 km/h) | 81.48 mph (131.13 km/h) |
| 85 mph (136.79 km/h) | 86.57 mph (139.32 km/h) |
| 90 mph (144.84 km/h) | 91.66 mph (147.52 km/h) |
| 95 mph (152.89 km/h) | 96.76 mph (155.71 km/h) |
| 100 mph (160.93 km/h) | 101.85 mph (163.91 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 | 2291 | 2467 | 2576 | 2694 | 2778 | 2870 | 2979 | 3130 | 3281 | 3449 | 3584 | 3827 | 4095 | 4305 | 4440 | 4515 | 4792 | 5178 | 6017 |
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