Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 215/30-20 | 315/30-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.08 (637) | 25.44 (646.2) | 0.36 (9.2) 1.4% |
| Width inches (mm) | 8.46 (215) | 12.4 (315) | 3.94 (100) 46.5% |
| Circum. inches (mm) | 78.79 (2001.19) | 79.93 (2030.1) | 1.14 (28.9) 1.4% |
| Sidewall Height inches (mm) | 2.54 (64.5) | 3.72 (94.5) | 1.18 (30) 46.5% |
| Revolutions per mile (km) | 804.19 (499.7) | 792.74 (492.59) | -11.45 (-7.11) -1.4% |
315/30-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.29 mph (32.65 km/h) |
| 25 mph (40.23 km/h) | 25.36 mph (40.81 km/h) |
| 30 mph (48.28 km/h) | 30.43 mph (48.98 km/h) |
| 35 mph (56.33 km/h) | 35.51 mph (57.14 km/h) |
| 40 mph (64.37 km/h) | 40.58 mph (65.3 km/h) |
| 45 mph (72.42 km/h) | 45.65 mph (73.47 km/h) |
| 50 mph (80.47 km/h) | 50.72 mph (81.63 km/h) |
| 55 mph (88.51 km/h) | 55.79 mph (89.79 km/h) |
| 60 mph (96.56 km/h) | 60.87 mph (97.96 km/h) |
| 65 mph (104.61 km/h) | 65.94 mph (106.12 km/h) |
| 70 mph (112.65 km/h) | 71.01 mph (114.28 km/h) |
| 75 mph (120.7 km/h) | 76.08 mph (122.44 km/h) |
| 80 mph (128.75 km/h) | 81.16 mph (130.61 km/h) |
| 85 mph (136.79 km/h) | 86.23 mph (138.77 km/h) |
| 90 mph (144.84 km/h) | 91.3 mph (146.93 km/h) |
| 95 mph (152.89 km/h) | 96.37 mph (155.1 km/h) |
| 100 mph (160.93 km/h) | 101.44 mph (163.26 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2017 | 2344 | 2524 | 2635 | 2756 | 2841 | 2936 | 3048 | 3202 | 3357 | 3528 | 3666 | 3915 | 4189 | 4404 | 4541 | 4619 | 4902 | 5297 | 6155 |
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