Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 100/90-21 | 120/90-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.09 (713.4) | 26.5 (673.2) | -1.58 (-40.2) -5.6% |
| Width inches (mm) | 3.94 (100) | 4.72 (120) | 0.79 (20) 20% |
| Circum. inches (mm) | 88.24 (2241.21) | 83.26 (2114.92) | -4.97 (-126.29) -5.6% |
| Sidewall Height inches (mm) | 3.54 (90) | 4.25 (108) | 0.71 (18) 20% |
| Revolutions per mile (km) | 718.07 (446.19) | 760.95 (472.83) | 42.88 (26.64) 6% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.87 mph (30.37 km/h) |
| 25 mph (40.23 km/h) | 23.59 mph (37.97 km/h) |
| 30 mph (48.28 km/h) | 28.31 mph (45.56 km/h) |
| 35 mph (56.33 km/h) | 33.03 mph (53.15 km/h) |
| 40 mph (64.37 km/h) | 37.75 mph (60.75 km/h) |
| 45 mph (72.42 km/h) | 42.46 mph (68.34 km/h) |
| 50 mph (80.47 km/h) | 47.18 mph (75.93 km/h) |
| 55 mph (88.51 km/h) | 51.9 mph (83.53 km/h) |
| 60 mph (96.56 km/h) | 56.62 mph (91.12 km/h) |
| 65 mph (104.61 km/h) | 61.34 mph (98.71 km/h) |
| 70 mph (112.65 km/h) | 66.06 mph (106.31 km/h) |
| 75 mph (120.7 km/h) | 70.77 mph (113.9 km/h) |
| 80 mph (128.75 km/h) | 75.49 mph (121.49 km/h) |
| 85 mph (136.79 km/h) | 80.21 mph (129.09 km/h) |
| 90 mph (144.84 km/h) | 84.93 mph (136.68 km/h) |
| 95 mph (152.89 km/h) | 89.65 mph (144.27 km/h) |
| 100 mph (160.93 km/h) | 94.37 mph (151.87 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1936 | 2250 | 2423 | 2530 | 2645 | 2728 | 2818 | 2925 | 3074 | 3222 | 3387 | 3519 | 3758 | 4021 | 4227 | 4359 | 4433 | 4705 | 5084 | 5908 |
Better Fuel Economy Factory Ratios Increased Power
