Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 245/40-18 | 245/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.72 (653.2) | 27.72 (704) | 2 (50.8) 7.8% |
| Width inches (mm) | 9.65 (245) | 9.65 (245) | 0 (0) 0% |
| Circum. inches (mm) | 80.79 (2052.09) | 87.07 (2211.68) | 6.28 (159.59) 7.8% |
| Sidewall Height inches (mm) | 3.86 (98) | 3.86 (98) | 0 (0) 0% |
| Revolutions per mile (km) | 784.25 (487.31) | 727.66 (452.14) | -56.59 (-35.16) -7.2% |
245/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.56 mph (34.69 km/h) |
| 25 mph (40.23 km/h) | 26.94 mph (43.36 km/h) |
| 30 mph (48.28 km/h) | 32.33 mph (52.04 km/h) |
| 35 mph (56.33 km/h) | 37.72 mph (60.71 km/h) |
| 40 mph (64.37 km/h) | 43.11 mph (69.38 km/h) |
| 45 mph (72.42 km/h) | 48.5 mph (78.05 km/h) |
| 50 mph (80.47 km/h) | 53.89 mph (86.73 km/h) |
| 55 mph (88.51 km/h) | 59.28 mph (95.4 km/h) |
| 60 mph (96.56 km/h) | 64.67 mph (104.07 km/h) |
| 65 mph (104.61 km/h) | 70.06 mph (112.74 km/h) |
| 70 mph (112.65 km/h) | 75.44 mph (121.42 km/h) |
| 75 mph (120.7 km/h) | 80.83 mph (130.09 km/h) |
| 80 mph (128.75 km/h) | 86.22 mph (138.76 km/h) |
| 85 mph (136.79 km/h) | 91.61 mph (147.43 km/h) |
| 90 mph (144.84 km/h) | 97 mph (156.11 km/h) |
| 95 mph (152.89 km/h) | 102.39 mph (164.78 km/h) |
| 100 mph (160.93 km/h) | 107.78 mph (173.45 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1852 | 2151 | 2317 | 2419 | 2529 | 2608 | 2695 | 2797 | 2939 | 3081 | 3239 | 3365 | 3593 | 3845 | 4042 | 4168 | 4239 | 4499 | 4862 | 5650 |
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