Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 90/90-21 | 120/80-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.38 (695.4) | 25.56 (649.2) | -1.82 (-46.2) -6.6% |
| Width inches (mm) | 3.54 (90) | 4.72 (120) | 1.18 (30) 33.3% |
| Circum. inches (mm) | 86.01 (2184.66) | 80.3 (2039.52) | -5.71 (-145.14) -6.6% |
| Sidewall Height inches (mm) | 3.19 (81) | 3.78 (96) | 0.59 (15) 18.5% |
| Revolutions per mile (km) | 736.66 (457.74) | 789.08 (490.31) | 52.42 (32.57) 7.1% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.67 mph (30.05 km/h) |
| 25 mph (40.23 km/h) | 23.34 mph (37.56 km/h) |
| 30 mph (48.28 km/h) | 28.01 mph (45.07 km/h) |
| 35 mph (56.33 km/h) | 32.67 mph (52.58 km/h) |
| 40 mph (64.37 km/h) | 37.34 mph (60.1 km/h) |
| 45 mph (72.42 km/h) | 42.01 mph (67.61 km/h) |
| 50 mph (80.47 km/h) | 46.68 mph (75.12 km/h) |
| 55 mph (88.51 km/h) | 51.35 mph (82.63 km/h) |
| 60 mph (96.56 km/h) | 56.01 mph (90.15 km/h) |
| 65 mph (104.61 km/h) | 60.68 mph (97.66 km/h) |
| 70 mph (112.65 km/h) | 65.35 mph (105.17 km/h) |
| 75 mph (120.7 km/h) | 70.02 mph (112.68 km/h) |
| 80 mph (128.75 km/h) | 74.69 mph (120.19 km/h) |
| 85 mph (136.79 km/h) | 79.35 mph (127.71 km/h) |
| 90 mph (144.84 km/h) | 84.02 mph (135.22 km/h) |
| 95 mph (152.89 km/h) | 88.69 mph (142.73 km/h) |
| 100 mph (160.93 km/h) | 93.36 mph (150.24 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2008 | 2333 | 2512 | 2623 | 2743 | 2828 | 2922 | 3033 | 3187 | 3341 | 3512 | 3649 | 3896 | 4170 | 4384 | 4520 | 4597 | 4879 | 5272 | 6127 |
Better Fuel Economy Factory Ratios Increased Power
