Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/40-21 | 275/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.98 (761.4) | 30.74 (780.9) | 0.77 (19.5) 2.6% |
| Width inches (mm) | 11.22 (285) | 10.83 (275) | -0.39 (-10) -3.5% |
| Circum. inches (mm) | 94.17 (2392.01) | 96.59 (2453.27) | 2.41 (61.26) 2.6% |
| Sidewall Height inches (mm) | 4.49 (114) | 4.87 (123.75) | 0.38 (9.75) 8.6% |
| Revolutions per mile (km) | 672.8 (418.06) | 656 (407.62) | -16.8 (-10.44) -2.5% |
275/45-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.51 mph (33.01 km/h) |
| 25 mph (40.23 km/h) | 25.64 mph (41.26 km/h) |
| 30 mph (48.28 km/h) | 30.77 mph (49.52 km/h) |
| 35 mph (56.33 km/h) | 35.9 mph (57.77 km/h) |
| 40 mph (64.37 km/h) | 41.02 mph (66.02 km/h) |
| 45 mph (72.42 km/h) | 46.15 mph (74.28 km/h) |
| 50 mph (80.47 km/h) | 51.28 mph (82.53 km/h) |
| 55 mph (88.51 km/h) | 56.41 mph (90.78 km/h) |
| 60 mph (96.56 km/h) | 61.54 mph (99.03 km/h) |
| 65 mph (104.61 km/h) | 66.66 mph (107.29 km/h) |
| 70 mph (112.65 km/h) | 71.79 mph (115.54 km/h) |
| 75 mph (120.7 km/h) | 76.92 mph (123.79 km/h) |
| 80 mph (128.75 km/h) | 82.05 mph (132.05 km/h) |
| 85 mph (136.79 km/h) | 87.18 mph (140.3 km/h) |
| 90 mph (144.84 km/h) | 92.3 mph (148.55 km/h) |
| 95 mph (152.89 km/h) | 97.43 mph (156.8 km/h) |
| 100 mph (160.93 km/h) | 102.56 mph (165.06 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
