Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 100/90-21 | 70/90-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.09 (713.4) | 25.96 (659.4) | -2.13 (-54) -7.6% |
| Width inches (mm) | 3.94 (100) | 2.76 (70) | -1.18 (-30) -30% |
| Circum. inches (mm) | 88.24 (2241.21) | 81.56 (2071.57) | -6.68 (-169.65) -7.6% |
| Sidewall Height inches (mm) | 3.54 (90) | 2.48 (63) | -1.06 (-27) -30% |
| Revolutions per mile (km) | 718.07 (446.19) | 776.87 (482.73) | 58.8 (36.54) 8.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.49 mph (29.75 km/h) |
| 25 mph (40.23 km/h) | 23.11 mph (37.19 km/h) |
| 30 mph (48.28 km/h) | 27.73 mph (44.63 km/h) |
| 35 mph (56.33 km/h) | 32.35 mph (52.06 km/h) |
| 40 mph (64.37 km/h) | 36.97 mph (59.5 km/h) |
| 45 mph (72.42 km/h) | 41.59 mph (66.94 km/h) |
| 50 mph (80.47 km/h) | 46.22 mph (74.38 km/h) |
| 55 mph (88.51 km/h) | 50.84 mph (81.81 km/h) |
| 60 mph (96.56 km/h) | 55.46 mph (89.25 km/h) |
| 65 mph (104.61 km/h) | 60.08 mph (96.69 km/h) |
| 70 mph (112.65 km/h) | 64.7 mph (104.13 km/h) |
| 75 mph (120.7 km/h) | 69.32 mph (111.56 km/h) |
| 80 mph (128.75 km/h) | 73.94 mph (119 km/h) |
| 85 mph (136.79 km/h) | 78.57 mph (126.44 km/h) |
| 90 mph (144.84 km/h) | 83.19 mph (133.88 km/h) |
| 95 mph (152.89 km/h) | 87.81 mph (141.32 km/h) |
| 100 mph (160.93 km/h) | 92.43 mph (148.75 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1977 | 2297 | 2473 | 2583 | 2700 | 2785 | 2877 | 2987 | 3138 | 3289 | 3458 | 3592 | 3836 | 4105 | 4316 | 4450 | 4526 | 4804 | 5191 | 6032 |
Better Fuel Economy Factory Ratios Increased Power
