Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 155/70-15 | 145/55-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 23.54 (598) | 27.28 (692.9) | 3.74 (94.9) 15.9% |
| Width inches (mm) | 6.1 (155) | 5.71 (145) | -0.39 (-10) -6.5% |
| Circum. inches (mm) | 73.96 (1878.67) | 85.7 (2176.81) | 11.74 (298.14) 15.9% |
| Sidewall Height inches (mm) | 4.27 (108.5) | 3.14 (79.75) | -1.13 (-28.75) -26.5% |
| Revolutions per mile (km) | 856.64 (532.29) | 739.31 (459.39) | -117.33 (-72.9) -13.7% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 23.17 mph (37.29 km/h) |
| 25 mph (40.23 km/h) | 28.97 mph (46.62 km/h) |
| 30 mph (48.28 km/h) | 34.76 mph (55.94 km/h) |
| 35 mph (56.33 km/h) | 40.55 mph (65.27 km/h) |
| 40 mph (64.37 km/h) | 46.35 mph (74.59 km/h) |
| 45 mph (72.42 km/h) | 52.14 mph (83.91 km/h) |
| 50 mph (80.47 km/h) | 57.93 mph (93.24 km/h) |
| 55 mph (88.51 km/h) | 63.73 mph (102.56 km/h) |
| 60 mph (96.56 km/h) | 69.52 mph (111.88 km/h) |
| 65 mph (104.61 km/h) | 75.32 mph (121.21 km/h) |
| 70 mph (112.65 km/h) | 81.11 mph (130.53 km/h) |
| 75 mph (120.7 km/h) | 86.9 mph (139.86 km/h) |
| 80 mph (128.75 km/h) | 92.7 mph (149.18 km/h) |
| 85 mph (136.79 km/h) | 98.49 mph (158.5 km/h) |
| 90 mph (144.84 km/h) | 104.28 mph (167.83 km/h) |
| 95 mph (152.89 km/h) | 110.08 mph (177.15 km/h) |
| 100 mph (160.93 km/h) | 115.87 mph (186.47 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1881 | 2186 | 2354 | 2458 | 2570 | 2650 | 2738 | 2842 | 2986 | 3130 | 3290 | 3419 | 3651 | 3907 | 4107 | 4235 | 4307 | 4571 | 4940 | 5740 |
Better Fuel Economy Factory Ratios Increased Power
