Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/25-21 | 305/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.4 (695.9) | 27.2 (691) | -0.19 (-4.9) -0.7% |
| Width inches (mm) | 12.8 (325) | 12.01 (305) | -0.79 (-20) -6.2% |
| Circum. inches (mm) | 86.07 (2186.23) | 85.47 (2170.84) | -0.61 (-15.39) -0.7% |
| Sidewall Height inches (mm) | 3.2 (81.25) | 3.6 (91.5) | 0.4 (10.25) 12.6% |
| Revolutions per mile (km) | 736.13 (457.41) | 741.35 (460.65) | 5.22 (3.24) 0.7% |
305/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.86 mph (31.96 km/h) |
| 25 mph (40.23 km/h) | 24.82 mph (39.95 km/h) |
| 30 mph (48.28 km/h) | 29.79 mph (47.94 km/h) |
| 35 mph (56.33 km/h) | 34.75 mph (55.93 km/h) |
| 40 mph (64.37 km/h) | 39.72 mph (63.92 km/h) |
| 45 mph (72.42 km/h) | 44.68 mph (71.91 km/h) |
| 50 mph (80.47 km/h) | 49.65 mph (79.9 km/h) |
| 55 mph (88.51 km/h) | 54.61 mph (87.89 km/h) |
| 60 mph (96.56 km/h) | 59.58 mph (95.88 km/h) |
| 65 mph (104.61 km/h) | 64.54 mph (103.87 km/h) |
| 70 mph (112.65 km/h) | 69.51 mph (111.86 km/h) |
| 75 mph (120.7 km/h) | 74.47 mph (119.85 km/h) |
| 80 mph (128.75 km/h) | 79.44 mph (127.84 km/h) |
| 85 mph (136.79 km/h) | 84.4 mph (135.83 km/h) |
| 90 mph (144.84 km/h) | 89.37 mph (143.82 km/h) |
| 95 mph (152.89 km/h) | 94.33 mph (151.81 km/h) |
| 100 mph (160.93 km/h) | 99.3 mph (159.8 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1887 | 2192 | 2360 | 2465 | 2577 | 2657 | 2746 | 2850 | 2994 | 3139 | 3300 | 3428 | 3661 | 3918 | 4118 | 4247 | 4319 | 4584 | 4953 | 5756 |
Better Fuel Economy Factory Ratios Increased Power
