Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/30-21 | 285/35-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.2 (716.4) | 28.85 (732.9) | 0.65 (16.5) 2.3% |
| Width inches (mm) | 12.01 (305) | 11.22 (285) | -0.79 (-20) -6.6% |
| Circum. inches (mm) | 88.61 (2250.64) | 90.65 (2302.47) | 2.04 (51.84) 2.3% |
| Sidewall Height inches (mm) | 3.6 (91.5) | 3.93 (99.75) | 0.32 (8.25) 9% |
| Revolutions per mile (km) | 715.06 (444.32) | 698.96 (434.31) | -16.1 (-10) -2.3% |
285/35-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.46 mph (32.93 km/h) |
| 25 mph (40.23 km/h) | 25.58 mph (41.16 km/h) |
| 30 mph (48.28 km/h) | 30.69 mph (49.39 km/h) |
| 35 mph (56.33 km/h) | 35.81 mph (57.62 km/h) |
| 40 mph (64.37 km/h) | 40.92 mph (65.86 km/h) |
| 45 mph (72.42 km/h) | 46.04 mph (74.09 km/h) |
| 50 mph (80.47 km/h) | 51.15 mph (82.32 km/h) |
| 55 mph (88.51 km/h) | 56.27 mph (90.55 km/h) |
| 60 mph (96.56 km/h) | 61.38 mph (98.78 km/h) |
| 65 mph (104.61 km/h) | 66.5 mph (107.02 km/h) |
| 70 mph (112.65 km/h) | 71.61 mph (115.25 km/h) |
| 75 mph (120.7 km/h) | 76.73 mph (123.48 km/h) |
| 80 mph (128.75 km/h) | 81.84 mph (131.71 km/h) |
| 85 mph (136.79 km/h) | 86.96 mph (139.95 km/h) |
| 90 mph (144.84 km/h) | 92.07 mph (148.18 km/h) |
| 95 mph (152.89 km/h) | 97.19 mph (156.41 km/h) |
| 100 mph (160.93 km/h) | 102.3 mph (164.64 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1779 | 2066 | 2225 | 2324 | 2430 | 2505 | 2589 | 2687 | 2823 | 2960 | 3111 | 3232 | 3451 | 3694 | 3883 | 4004 | 4072 | 4322 | 4670 | 5427 |
Better Fuel Economy Factory Ratios Increased Power
