Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 80/100-21 | 120/90-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.3 (693.4) | 26.5 (673.2) | -0.8 (-20.2) -2.9% |
| Width inches (mm) | 3.15 (80) | 4.72 (120) | 1.57 (40) 50% |
| Circum. inches (mm) | 85.76 (2178.38) | 83.26 (2114.92) | -2.5 (-63.46) -2.9% |
| Sidewall Height inches (mm) | 3.15 (80) | 4.25 (108) | 1.1 (28) 35% |
| Revolutions per mile (km) | 738.78 (459.06) | 760.95 (472.83) | 22.17 (13.77) 3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.42 mph (31.25 km/h) |
| 25 mph (40.23 km/h) | 24.27 mph (39.06 km/h) |
| 30 mph (48.28 km/h) | 29.13 mph (46.87 km/h) |
| 35 mph (56.33 km/h) | 33.98 mph (54.69 km/h) |
| 40 mph (64.37 km/h) | 38.83 mph (62.5 km/h) |
| 45 mph (72.42 km/h) | 43.69 mph (70.31 km/h) |
| 50 mph (80.47 km/h) | 48.54 mph (78.12 km/h) |
| 55 mph (88.51 km/h) | 53.4 mph (85.94 km/h) |
| 60 mph (96.56 km/h) | 58.25 mph (93.75 km/h) |
| 65 mph (104.61 km/h) | 63.11 mph (101.56 km/h) |
| 70 mph (112.65 km/h) | 67.96 mph (109.37 km/h) |
| 75 mph (120.7 km/h) | 72.82 mph (117.18 km/h) |
| 80 mph (128.75 km/h) | 77.67 mph (125 km/h) |
| 85 mph (136.79 km/h) | 82.52 mph (132.81 km/h) |
| 90 mph (144.84 km/h) | 87.38 mph (140.62 km/h) |
| 95 mph (152.89 km/h) | 92.23 mph (148.43 km/h) |
| 100 mph (160.93 km/h) | 97.09 mph (156.25 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
