Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 245/30-21 | 245/40-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.79 (680.4) | 28.72 (729.4) | 1.93 (49) 7.2% |
| Width inches (mm) | 9.65 (245) | 9.65 (245) | 0 (0) 0% |
| Circum. inches (mm) | 84.16 (2137.54) | 90.22 (2291.48) | 6.06 (153.94) 7.2% |
| Sidewall Height inches (mm) | 2.89 (73.5) | 3.86 (98) | 0.96 (24.5) 33.3% |
| Revolutions per mile (km) | 752.9 (467.83) | 702.32 (436.4) | -50.58 (-31.43) -6.7% |
245/40-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.44 mph (34.5 km/h) |
| 25 mph (40.23 km/h) | 26.8 mph (43.13 km/h) |
| 30 mph (48.28 km/h) | 32.16 mph (51.76 km/h) |
| 35 mph (56.33 km/h) | 37.52 mph (60.38 km/h) |
| 40 mph (64.37 km/h) | 42.88 mph (69.01 km/h) |
| 45 mph (72.42 km/h) | 48.24 mph (77.64 km/h) |
| 50 mph (80.47 km/h) | 53.6 mph (86.26 km/h) |
| 55 mph (88.51 km/h) | 58.96 mph (94.89 km/h) |
| 60 mph (96.56 km/h) | 64.32 mph (103.51 km/h) |
| 65 mph (104.61 km/h) | 69.68 mph (112.14 km/h) |
| 70 mph (112.65 km/h) | 75.04 mph (120.77 km/h) |
| 75 mph (120.7 km/h) | 80.4 mph (129.39 km/h) |
| 80 mph (128.75 km/h) | 85.76 mph (138.02 km/h) |
| 85 mph (136.79 km/h) | 91.12 mph (146.65 km/h) |
| 90 mph (144.84 km/h) | 96.48 mph (155.27 km/h) |
| 95 mph (152.89 km/h) | 101.84 mph (163.9 km/h) |
| 100 mph (160.93 km/h) | 107.2 mph (172.52 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1787 | 2076 | 2236 | 2335 | 2441 | 2517 | 2601 | 2700 | 2837 | 2974 | 3126 | 3247 | 3468 | 3711 | 3902 | 4023 | 4092 | 4343 | 4693 | 5453 |
Better Fuel Economy Factory Ratios Increased Power
