Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 180/70-18 | 90/100-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.92 (709.2) | 28.09 (713.4) | 0.17 (4.2) 0.6% |
| Width inches (mm) | 7.09 (180) | 3.54 (90) | -3.54 (-90) -50% |
| Circum. inches (mm) | 87.72 (2228.02) | 88.24 (2241.21) | 0.52 (13.19) 0.6% |
| Sidewall Height inches (mm) | 4.96 (126) | 3.54 (90) | -1.42 (-36) -28.6% |
| Revolutions per mile (km) | 722.32 (448.83) | 718.07 (446.19) | -4.25 (-2.64) -0.6% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.12 mph (32.38 km/h) |
| 25 mph (40.23 km/h) | 25.15 mph (40.47 km/h) |
| 30 mph (48.28 km/h) | 30.18 mph (48.57 km/h) |
| 35 mph (56.33 km/h) | 35.21 mph (56.66 km/h) |
| 40 mph (64.37 km/h) | 40.24 mph (64.76 km/h) |
| 45 mph (72.42 km/h) | 45.27 mph (72.85 km/h) |
| 50 mph (80.47 km/h) | 50.3 mph (80.94 km/h) |
| 55 mph (88.51 km/h) | 55.33 mph (89.04 km/h) |
| 60 mph (96.56 km/h) | 60.36 mph (97.13 km/h) |
| 65 mph (104.61 km/h) | 65.38 mph (105.23 km/h) |
| 70 mph (112.65 km/h) | 70.41 mph (113.32 km/h) |
| 75 mph (120.7 km/h) | 75.44 mph (121.42 km/h) |
| 80 mph (128.75 km/h) | 80.47 mph (129.51 km/h) |
| 85 mph (136.79 km/h) | 85.5 mph (137.6 km/h) |
| 90 mph (144.84 km/h) | 90.53 mph (145.7 km/h) |
| 95 mph (152.89 km/h) | 95.56 mph (153.79 km/h) |
| 100 mph (160.93 km/h) | 100.59 mph (161.89 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
