Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/30-20 | 245/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.55 (649) | 25.72 (653.2) | 0.17 (4.2) 0.6% |
| Width inches (mm) | 9.25 (235) | 9.65 (245) | 0.39 (10) 4.3% |
| Circum. inches (mm) | 80.27 (2038.89) | 80.79 (2052.09) | 0.52 (13.19) 0.6% |
| Sidewall Height inches (mm) | 2.78 (70.5) | 3.86 (98) | 1.08 (27.5) 39% |
| Revolutions per mile (km) | 789.32 (490.46) | 784.25 (487.31) | -5.08 (-3.15) -0.6% |
245/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.13 mph (32.4 km/h) |
| 25 mph (40.23 km/h) | 25.16 mph (40.49 km/h) |
| 30 mph (48.28 km/h) | 30.19 mph (48.59 km/h) |
| 35 mph (56.33 km/h) | 35.23 mph (56.69 km/h) |
| 40 mph (64.37 km/h) | 40.26 mph (64.79 km/h) |
| 45 mph (72.42 km/h) | 45.29 mph (72.89 km/h) |
| 50 mph (80.47 km/h) | 50.32 mph (80.99 km/h) |
| 55 mph (88.51 km/h) | 55.36 mph (89.09 km/h) |
| 60 mph (96.56 km/h) | 60.39 mph (97.19 km/h) |
| 65 mph (104.61 km/h) | 65.42 mph (105.28 km/h) |
| 70 mph (112.65 km/h) | 70.45 mph (113.38 km/h) |
| 75 mph (120.7 km/h) | 75.49 mph (121.48 km/h) |
| 80 mph (128.75 km/h) | 80.52 mph (129.58 km/h) |
| 85 mph (136.79 km/h) | 85.55 mph (137.68 km/h) |
| 90 mph (144.84 km/h) | 90.58 mph (145.78 km/h) |
| 95 mph (152.89 km/h) | 95.61 mph (153.88 km/h) |
| 100 mph (160.93 km/h) | 100.65 mph (161.98 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1996 | 2318 | 2497 | 2607 | 2726 | 2811 | 2904 | 3015 | 3168 | 3321 | 3490 | 3626 | 3873 | 4144 | 4357 | 4493 | 4569 | 4849 | 5240 | 6089 |
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