Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 90/90-21 | 120/90-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.38 (695.4) | 29.5 (749.4) | 2.13 (54) 7.8% |
| Width inches (mm) | 3.54 (90) | 4.72 (120) | 1.18 (30) 33.3% |
| Circum. inches (mm) | 86.01 (2184.66) | 92.69 (2354.31) | 6.68 (169.65) 7.8% |
| Sidewall Height inches (mm) | 3.19 (81) | 4.25 (108) | 1.06 (27) 33.3% |
| Revolutions per mile (km) | 736.66 (457.74) | 683.57 (424.75) | -53.08 (-32.98) -7.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.55 mph (34.69 km/h) |
| 25 mph (40.23 km/h) | 26.94 mph (43.36 km/h) |
| 30 mph (48.28 km/h) | 32.33 mph (52.03 km/h) |
| 35 mph (56.33 km/h) | 37.72 mph (60.7 km/h) |
| 40 mph (64.37 km/h) | 43.11 mph (69.37 km/h) |
| 45 mph (72.42 km/h) | 48.49 mph (78.04 km/h) |
| 50 mph (80.47 km/h) | 53.88 mph (86.72 km/h) |
| 55 mph (88.51 km/h) | 59.27 mph (95.39 km/h) |
| 60 mph (96.56 km/h) | 64.66 mph (104.06 km/h) |
| 65 mph (104.61 km/h) | 70.05 mph (112.73 km/h) |
| 70 mph (112.65 km/h) | 75.44 mph (121.4 km/h) |
| 75 mph (120.7 km/h) | 80.82 mph (130.07 km/h) |
| 80 mph (128.75 km/h) | 86.21 mph (138.75 km/h) |
| 85 mph (136.79 km/h) | 91.6 mph (147.42 km/h) |
| 90 mph (144.84 km/h) | 96.99 mph (156.09 km/h) |
| 95 mph (152.89 km/h) | 102.38 mph (164.76 km/h) |
| 100 mph (160.93 km/h) | 107.77 mph (173.43 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1740 | 2021 | 2176 | 2273 | 2376 | 2450 | 2532 | 2628 | 2761 | 2894 | 3042 | 3161 | 3375 | 3612 | 3797 | 3916 | 3982 | 4227 | 4567 | 5308 |
Better Fuel Economy Factory Ratios Increased Power
