Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 245/40-21 | 245/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.72 (729.4) | 27.72 (704) | -1 (-25.4) -3.5% |
| Width inches (mm) | 9.65 (245) | 9.65 (245) | 0 (0) 0% |
| Circum. inches (mm) | 90.22 (2291.48) | 87.07 (2211.68) | -3.14 (-79.8) -3.5% |
| Sidewall Height inches (mm) | 3.86 (98) | 3.86 (98) | 0 (0) 0% |
| Revolutions per mile (km) | 702.32 (436.4) | 727.66 (452.14) | 25.34 (15.75) 3.6% |
245/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.3 mph (31.07 km/h) |
| 25 mph (40.23 km/h) | 24.13 mph (38.83 km/h) |
| 30 mph (48.28 km/h) | 28.96 mph (46.6 km/h) |
| 35 mph (56.33 km/h) | 33.78 mph (54.37 km/h) |
| 40 mph (64.37 km/h) | 38.61 mph (62.13 km/h) |
| 45 mph (72.42 km/h) | 43.43 mph (69.9 km/h) |
| 50 mph (80.47 km/h) | 48.26 mph (77.67 km/h) |
| 55 mph (88.51 km/h) | 53.08 mph (85.43 km/h) |
| 60 mph (96.56 km/h) | 57.91 mph (93.2 km/h) |
| 65 mph (104.61 km/h) | 62.74 mph (100.96 km/h) |
| 70 mph (112.65 km/h) | 67.56 mph (108.73 km/h) |
| 75 mph (120.7 km/h) | 72.39 mph (116.5 km/h) |
| 80 mph (128.75 km/h) | 77.21 mph (124.26 km/h) |
| 85 mph (136.79 km/h) | 82.04 mph (132.03 km/h) |
| 90 mph (144.84 km/h) | 86.87 mph (139.8 km/h) |
| 95 mph (152.89 km/h) | 91.69 mph (147.56 km/h) |
| 100 mph (160.93 km/h) | 96.52 mph (155.33 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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