Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/50-20 | 275/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.22 (793) | 30.74 (780.9) | -0.48 (-12.1) -1.5% |
| Width inches (mm) | 11.22 (285) | 10.83 (275) | -0.39 (-10) -3.5% |
| Circum. inches (mm) | 98.08 (2491.28) | 96.59 (2453.27) | -1.5 (-38.01) -1.5% |
| Sidewall Height inches (mm) | 5.61 (142.5) | 4.87 (123.75) | -0.74 (-18.75) -13.2% |
| Revolutions per mile (km) | 645.99 (401.4) | 656 (407.62) | 10.01 (6.22) 1.5% |
275/45-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.69 mph (31.7 km/h) |
| 25 mph (40.23 km/h) | 24.62 mph (39.62 km/h) |
| 30 mph (48.28 km/h) | 29.54 mph (47.54 km/h) |
| 35 mph (56.33 km/h) | 34.47 mph (55.47 km/h) |
| 40 mph (64.37 km/h) | 39.39 mph (63.39 km/h) |
| 45 mph (72.42 km/h) | 44.31 mph (71.32 km/h) |
| 50 mph (80.47 km/h) | 49.24 mph (79.24 km/h) |
| 55 mph (88.51 km/h) | 54.16 mph (87.16 km/h) |
| 60 mph (96.56 km/h) | 59.08 mph (95.09 km/h) |
| 65 mph (104.61 km/h) | 64.01 mph (103.01 km/h) |
| 70 mph (112.65 km/h) | 68.93 mph (110.94 km/h) |
| 75 mph (120.7 km/h) | 73.86 mph (118.86 km/h) |
| 80 mph (128.75 km/h) | 78.78 mph (126.78 km/h) |
| 85 mph (136.79 km/h) | 83.7 mph (134.71 km/h) |
| 90 mph (144.84 km/h) | 88.63 mph (142.63 km/h) |
| 95 mph (152.89 km/h) | 93.55 mph (150.56 km/h) |
| 100 mph (160.93 km/h) | 98.47 mph (158.48 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1669 | 1939 | 2089 | 2181 | 2280 | 2351 | 2430 | 2522 | 2650 | 2778 | 2920 | 3033 | 3239 | 3467 | 3644 | 3758 | 3822 | 4056 | 4383 | 5093 |
Better Fuel Economy Factory Ratios Increased Power
