Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 90/90-21 | 120/70-17 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.38 (695.4) | 23.61 (599.8) | -3.76 (-95.6) -13.7% |
| Width inches (mm) | 3.54 (90) | 4.72 (120) | 1.18 (30) 33.3% |
| Circum. inches (mm) | 86.01 (2184.66) | 74.19 (1884.33) | -11.82 (-300.34) -13.7% |
| Sidewall Height inches (mm) | 3.19 (81) | 3.31 (84) | 0.12 (3) 3.7% |
| Revolutions per mile (km) | 736.66 (457.74) | 854.07 (530.69) | 117.41 (72.96) 15.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.25 mph (27.76 km/h) |
| 25 mph (40.23 km/h) | 21.56 mph (34.7 km/h) |
| 30 mph (48.28 km/h) | 25.88 mph (41.64 km/h) |
| 35 mph (56.33 km/h) | 30.19 mph (48.58 km/h) |
| 40 mph (64.37 km/h) | 34.5 mph (55.52 km/h) |
| 45 mph (72.42 km/h) | 38.81 mph (62.46 km/h) |
| 50 mph (80.47 km/h) | 43.13 mph (69.41 km/h) |
| 55 mph (88.51 km/h) | 47.44 mph (76.35 km/h) |
| 60 mph (96.56 km/h) | 51.75 mph (83.29 km/h) |
| 65 mph (104.61 km/h) | 56.06 mph (90.23 km/h) |
| 70 mph (112.65 km/h) | 60.38 mph (97.17 km/h) |
| 75 mph (120.7 km/h) | 64.69 mph (104.11 km/h) |
| 80 mph (128.75 km/h) | 69 mph (111.05 km/h) |
| 85 mph (136.79 km/h) | 73.31 mph (117.99 km/h) |
| 90 mph (144.84 km/h) | 77.63 mph (124.93 km/h) |
| 95 mph (152.89 km/h) | 81.94 mph (131.87 km/h) |
| 100 mph (160.93 km/h) | 86.25 mph (138.81 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2173 | 2525 | 2719 | 2839 | 2969 | 3061 | 3163 | 3283 | 3450 | 3616 | 3801 | 3949 | 4217 | 4513 | 4745 | 4893 | 4976 | 5281 | 5706 | 6631 |
Better Fuel Economy Factory Ratios Increased Power
