Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 245/40-20 | 255/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.72 (704) | 26.02 (661) | -1.69 (-43) -6.1% |
| Width inches (mm) | 9.65 (245) | 10.04 (255) | 0.39 (10) 4.1% |
| Circum. inches (mm) | 87.07 (2211.68) | 81.76 (2076.59) | -5.32 (-135.09) -6.1% |
| Sidewall Height inches (mm) | 3.86 (98) | 3.01 (76.5) | -0.85 (-21.5) -21.9% |
| Revolutions per mile (km) | 727.66 (452.14) | 774.99 (481.56) | 47.34 (29.41) 6.5% |
255/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.78 mph (30.22 km/h) |
| 25 mph (40.23 km/h) | 23.47 mph (37.78 km/h) |
| 30 mph (48.28 km/h) | 28.17 mph (45.33 km/h) |
| 35 mph (56.33 km/h) | 32.86 mph (52.89 km/h) |
| 40 mph (64.37 km/h) | 37.56 mph (60.44 km/h) |
| 45 mph (72.42 km/h) | 42.25 mph (68 km/h) |
| 50 mph (80.47 km/h) | 46.95 mph (75.55 km/h) |
| 55 mph (88.51 km/h) | 51.64 mph (83.11 km/h) |
| 60 mph (96.56 km/h) | 56.34 mph (90.66 km/h) |
| 65 mph (104.61 km/h) | 61.03 mph (98.22 km/h) |
| 70 mph (112.65 km/h) | 65.72 mph (105.77 km/h) |
| 75 mph (120.7 km/h) | 70.42 mph (113.33 km/h) |
| 80 mph (128.75 km/h) | 75.11 mph (120.88 km/h) |
| 85 mph (136.79 km/h) | 79.81 mph (128.44 km/h) |
| 90 mph (144.84 km/h) | 84.5 mph (135.99 km/h) |
| 95 mph (152.89 km/h) | 89.2 mph (143.55 km/h) |
| 100 mph (160.93 km/h) | 93.89 mph (151.1 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1972 | 2291 | 2467 | 2576 | 2694 | 2778 | 2870 | 2979 | 3130 | 3281 | 3449 | 3584 | 3827 | 4095 | 4305 | 4440 | 4515 | 4792 | 5178 | 6017 |
Better Fuel Economy Factory Ratios Increased Power
