Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 155/70-18 | 255/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.54 (674.2) | 29.04 (737.5) | 2.49 (63.3) 9.4% |
| Width inches (mm) | 6.1 (155) | 10.04 (255) | 3.94 (100) 64.5% |
| Circum. inches (mm) | 83.39 (2118.06) | 91.22 (2316.92) | 7.83 (198.86) 9.4% |
| Sidewall Height inches (mm) | 4.27 (108.5) | 4.52 (114.75) | 0.25 (6.25) 5.8% |
| Revolutions per mile (km) | 759.82 (472.13) | 694.6 (431.61) | -65.22 (-40.52) -8.6% |
255/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.88 mph (35.21 km/h) |
| 25 mph (40.23 km/h) | 27.35 mph (44.01 km/h) |
| 30 mph (48.28 km/h) | 32.82 mph (52.81 km/h) |
| 35 mph (56.33 km/h) | 38.29 mph (61.62 km/h) |
| 40 mph (64.37 km/h) | 43.76 mph (70.42 km/h) |
| 45 mph (72.42 km/h) | 49.23 mph (79.22 km/h) |
| 50 mph (80.47 km/h) | 54.69 mph (88.02 km/h) |
| 55 mph (88.51 km/h) | 60.16 mph (96.82 km/h) |
| 60 mph (96.56 km/h) | 65.63 mph (105.63 km/h) |
| 65 mph (104.61 km/h) | 71.1 mph (114.43 km/h) |
| 70 mph (112.65 km/h) | 76.57 mph (123.23 km/h) |
| 75 mph (120.7 km/h) | 82.04 mph (132.03 km/h) |
| 80 mph (128.75 km/h) | 87.51 mph (140.84 km/h) |
| 85 mph (136.79 km/h) | 92.98 mph (149.64 km/h) |
| 90 mph (144.84 km/h) | 98.45 mph (158.44 km/h) |
| 95 mph (152.89 km/h) | 103.92 mph (167.24 km/h) |
| 100 mph (160.93 km/h) | 109.39 mph (176.04 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1768 | 2053 | 2211 | 2309 | 2415 | 2490 | 2572 | 2670 | 2806 | 2941 | 3091 | 3212 | 3430 | 3671 | 3859 | 3979 | 4047 | 4295 | 4641 | 5393 |
Better Fuel Economy Factory Ratios Increased Power
