Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 115/85-18 | 255/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.7 (652.7) | 29.04 (737.5) | 3.34 (84.8) 13% |
| Width inches (mm) | 4.53 (115) | 10.04 (255) | 5.51 (140) 121.7% |
| Circum. inches (mm) | 80.73 (2050.52) | 91.22 (2316.92) | 10.49 (266.41) 13% |
| Sidewall Height inches (mm) | 3.85 (97.75) | 4.52 (114.75) | 0.67 (17) 17.4% |
| Revolutions per mile (km) | 784.85 (487.68) | 694.6 (431.61) | -90.24 (-56.08) -11.5% |
255/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.6 mph (36.37 km/h) |
| 25 mph (40.23 km/h) | 28.25 mph (45.46 km/h) |
| 30 mph (48.28 km/h) | 33.9 mph (54.55 km/h) |
| 35 mph (56.33 km/h) | 39.55 mph (63.65 km/h) |
| 40 mph (64.37 km/h) | 45.2 mph (72.74 km/h) |
| 45 mph (72.42 km/h) | 50.85 mph (81.83 km/h) |
| 50 mph (80.47 km/h) | 56.5 mph (90.92 km/h) |
| 55 mph (88.51 km/h) | 62.15 mph (100.01 km/h) |
| 60 mph (96.56 km/h) | 67.8 mph (109.11 km/h) |
| 65 mph (104.61 km/h) | 73.44 mph (118.2 km/h) |
| 70 mph (112.65 km/h) | 79.09 mph (127.29 km/h) |
| 75 mph (120.7 km/h) | 84.74 mph (136.38 km/h) |
| 80 mph (128.75 km/h) | 90.39 mph (145.47 km/h) |
| 85 mph (136.79 km/h) | 96.04 mph (154.57 km/h) |
| 90 mph (144.84 km/h) | 101.69 mph (163.66 km/h) |
| 95 mph (152.89 km/h) | 107.34 mph (172.75 km/h) |
| 100 mph (160.93 km/h) | 112.99 mph (181.84 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1768 | 2053 | 2211 | 2309 | 2415 | 2490 | 2572 | 2670 | 2806 | 2941 | 3091 | 3212 | 3430 | 3671 | 3859 | 3979 | 4047 | 4295 | 4641 | 5393 |
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