Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/40-20 | 305/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.98 (736) | 29.61 (752) | 0.63 (16) 2.2% |
| Width inches (mm) | 11.22 (285) | 12.01 (305) | 0.79 (20) 7% |
| Circum. inches (mm) | 91.03 (2312.21) | 93.01 (2362.48) | 1.98 (50.27) 2.2% |
| Sidewall Height inches (mm) | 4.49 (114) | 4.8 (122) | 0.31 (8) 7% |
| Revolutions per mile (km) | 696.02 (432.49) | 681.21 (423.28) | -14.81 (-9.2) -2.1% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.43 mph (32.89 km/h) |
| 25 mph (40.23 km/h) | 25.54 mph (41.11 km/h) |
| 30 mph (48.28 km/h) | 30.65 mph (49.33 km/h) |
| 35 mph (56.33 km/h) | 35.76 mph (57.55 km/h) |
| 40 mph (64.37 km/h) | 40.87 mph (65.77 km/h) |
| 45 mph (72.42 km/h) | 45.98 mph (73.99 km/h) |
| 50 mph (80.47 km/h) | 51.09 mph (82.22 km/h) |
| 55 mph (88.51 km/h) | 56.2 mph (90.44 km/h) |
| 60 mph (96.56 km/h) | 61.3 mph (98.66 km/h) |
| 65 mph (104.61 km/h) | 66.41 mph (106.88 km/h) |
| 70 mph (112.65 km/h) | 71.52 mph (115.1 km/h) |
| 75 mph (120.7 km/h) | 76.63 mph (123.32 km/h) |
| 80 mph (128.75 km/h) | 81.74 mph (131.55 km/h) |
| 85 mph (136.79 km/h) | 86.85 mph (139.77 km/h) |
| 90 mph (144.84 km/h) | 91.96 mph (147.99 km/h) |
| 95 mph (152.89 km/h) | 97.07 mph (156.21 km/h) |
| 100 mph (160.93 km/h) | 102.17 mph (164.43 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1734 | 2014 | 2169 | 2265 | 2368 | 2442 | 2523 | 2619 | 2752 | 2884 | 3032 | 3150 | 3364 | 3600 | 3784 | 3902 | 3969 | 4212 | 4551 | 5289 |
Better Fuel Economy Factory Ratios Increased Power
