Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 120/70-21 | 100/90-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.61 (701.4) | 28.09 (713.4) | 0.47 (12) 1.7% |
| Width inches (mm) | 4.72 (120) | 3.94 (100) | -0.79 (-20) -16.7% |
| Circum. inches (mm) | 86.75 (2203.51) | 88.24 (2241.21) | 1.48 (37.7) 1.7% |
| Sidewall Height inches (mm) | 3.31 (84) | 3.54 (90) | 0.24 (6) 7.1% |
| Revolutions per mile (km) | 730.35 (453.82) | 718.07 (446.19) | -12.29 (-7.63) -1.7% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.34 mph (32.74 km/h) |
| 25 mph (40.23 km/h) | 25.43 mph (40.92 km/h) |
| 30 mph (48.28 km/h) | 30.51 mph (49.11 km/h) |
| 35 mph (56.33 km/h) | 35.6 mph (57.29 km/h) |
| 40 mph (64.37 km/h) | 40.68 mph (65.48 km/h) |
| 45 mph (72.42 km/h) | 45.77 mph (73.66 km/h) |
| 50 mph (80.47 km/h) | 50.86 mph (81.84 km/h) |
| 55 mph (88.51 km/h) | 55.94 mph (90.03 km/h) |
| 60 mph (96.56 km/h) | 61.03 mph (98.21 km/h) |
| 65 mph (104.61 km/h) | 66.11 mph (106.4 km/h) |
| 70 mph (112.65 km/h) | 71.2 mph (114.58 km/h) |
| 75 mph (120.7 km/h) | 76.28 mph (122.77 km/h) |
| 80 mph (128.75 km/h) | 81.37 mph (130.95 km/h) |
| 85 mph (136.79 km/h) | 86.45 mph (139.13 km/h) |
| 90 mph (144.84 km/h) | 91.54 mph (147.32 km/h) |
| 95 mph (152.89 km/h) | 96.63 mph (155.5 km/h) |
| 100 mph (160.93 km/h) | 101.71 mph (163.69 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1827 | 2123 | 2286 | 2387 | 2496 | 2574 | 2659 | 2760 | 2900 | 3040 | 3196 | 3320 | 3546 | 3795 | 3989 | 4113 | 4183 | 4440 | 4798 | 5575 |
Better Fuel Economy Factory Ratios Increased Power
