Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/25-21 | 255/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.41 (670.9) | 26.02 (661) | -0.39 (-9.9) -1.5% |
| Width inches (mm) | 10.83 (275) | 10.04 (255) | -0.79 (-20) -7.3% |
| Circum. inches (mm) | 82.98 (2107.69) | 81.76 (2076.59) | -1.22 (-31.1) -1.5% |
| Sidewall Height inches (mm) | 2.71 (68.75) | 3.01 (76.5) | 0.31 (7.75) 11.3% |
| Revolutions per mile (km) | 763.56 (474.45) | 774.99 (481.56) | 11.44 (7.11) 1.5% |
255/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.7 mph (31.71 km/h) |
| 25 mph (40.23 km/h) | 24.63 mph (39.64 km/h) |
| 30 mph (48.28 km/h) | 29.56 mph (47.57 km/h) |
| 35 mph (56.33 km/h) | 34.48 mph (55.5 km/h) |
| 40 mph (64.37 km/h) | 39.41 mph (63.42 km/h) |
| 45 mph (72.42 km/h) | 44.34 mph (71.35 km/h) |
| 50 mph (80.47 km/h) | 49.26 mph (79.28 km/h) |
| 55 mph (88.51 km/h) | 54.19 mph (87.21 km/h) |
| 60 mph (96.56 km/h) | 59.11 mph (95.14 km/h) |
| 65 mph (104.61 km/h) | 64.04 mph (103.06 km/h) |
| 70 mph (112.65 km/h) | 68.97 mph (110.99 km/h) |
| 75 mph (120.7 km/h) | 73.89 mph (118.92 km/h) |
| 80 mph (128.75 km/h) | 78.82 mph (126.85 km/h) |
| 85 mph (136.79 km/h) | 83.75 mph (134.78 km/h) |
| 90 mph (144.84 km/h) | 88.67 mph (142.7 km/h) |
| 95 mph (152.89 km/h) | 93.6 mph (150.63 km/h) |
| 100 mph (160.93 km/h) | 98.52 mph (158.56 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1972 | 2291 | 2467 | 2576 | 2694 | 2778 | 2870 | 2979 | 3130 | 3281 | 3449 | 3584 | 3827 | 4095 | 4305 | 4440 | 4515 | 4792 | 5178 | 6017 |
Better Fuel Economy Factory Ratios Increased Power
