Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/35-21 | 315/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.85 (732.9) | 28.44 (722.4) | -0.41 (-10.5) -1.4% |
| Width inches (mm) | 11.22 (285) | 12.4 (315) | 1.18 (30) 10.5% |
| Circum. inches (mm) | 90.65 (2302.47) | 89.35 (2269.49) | -1.3 (-32.99) -1.4% |
| Sidewall Height inches (mm) | 3.93 (99.75) | 3.72 (94.5) | -0.21 (-5.25) -5.3% |
| Revolutions per mile (km) | 698.96 (434.31) | 709.12 (440.63) | 10.16 (6.31) 1.5% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.71 mph (31.73 km/h) |
| 25 mph (40.23 km/h) | 24.64 mph (39.66 km/h) |
| 30 mph (48.28 km/h) | 29.57 mph (47.59 km/h) |
| 35 mph (56.33 km/h) | 34.5 mph (55.52 km/h) |
| 40 mph (64.37 km/h) | 39.43 mph (63.45 km/h) |
| 45 mph (72.42 km/h) | 44.36 mph (71.38 km/h) |
| 50 mph (80.47 km/h) | 49.28 mph (79.31 km/h) |
| 55 mph (88.51 km/h) | 54.21 mph (87.25 km/h) |
| 60 mph (96.56 km/h) | 59.14 mph (95.18 km/h) |
| 65 mph (104.61 km/h) | 64.07 mph (103.11 km/h) |
| 70 mph (112.65 km/h) | 69 mph (111.04 km/h) |
| 75 mph (120.7 km/h) | 73.93 mph (118.97 km/h) |
| 80 mph (128.75 km/h) | 78.85 mph (126.9 km/h) |
| 85 mph (136.79 km/h) | 83.78 mph (134.83 km/h) |
| 90 mph (144.84 km/h) | 88.71 mph (142.77 km/h) |
| 95 mph (152.89 km/h) | 93.64 mph (150.7 km/h) |
| 100 mph (160.93 km/h) | 98.57 mph (158.63 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1805 | 2096 | 2258 | 2357 | 2465 | 2542 | 2626 | 2726 | 2864 | 3003 | 3156 | 3279 | 3502 | 3747 | 3939 | 4062 | 4131 | 4385 | 4738 | 5506 |
Better Fuel Economy Factory Ratios Increased Power
