Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 40/12.5-20 | 305/65-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 40.03 (1016.8) | 35.61 (904.5) | -4.42 (-112.3) -11% |
| Width inches (mm) | 12.52 (318) | 12.01 (305) | -0.51 (-13) -4.1% |
| Circum. inches (mm) | 125.76 (3194.37) | 111.87 (2841.57) | -13.89 (-352.8) -11% |
| Sidewall Height inches (mm) | 10.02 (254.4) | 7.81 (198.25) | -2.21 (-56.15) -22.1% |
| Revolutions per mile (km) | 503.81 (313.05) | 566.36 (351.92) | 62.55 (38.87) 12.4% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.79 mph (28.63 km/h) |
| 25 mph (40.23 km/h) | 22.24 mph (35.79 km/h) |
| 30 mph (48.28 km/h) | 26.69 mph (42.95 km/h) |
| 35 mph (56.33 km/h) | 31.13 mph (50.11 km/h) |
| 40 mph (64.37 km/h) | 35.58 mph (57.26 km/h) |
| 45 mph (72.42 km/h) | 40.03 mph (64.42 km/h) |
| 50 mph (80.47 km/h) | 44.48 mph (71.58 km/h) |
| 55 mph (88.51 km/h) | 48.93 mph (78.74 km/h) |
| 60 mph (96.56 km/h) | 53.37 mph (85.9 km/h) |
| 65 mph (104.61 km/h) | 57.82 mph (93.05 km/h) |
| 70 mph (112.65 km/h) | 62.27 mph (100.21 km/h) |
| 75 mph (120.7 km/h) | 66.72 mph (107.37 km/h) |
| 80 mph (128.75 km/h) | 71.16 mph (114.53 km/h) |
| 85 mph (136.79 km/h) | 75.61 mph (121.69 km/h) |
| 90 mph (144.84 km/h) | 80.06 mph (128.84 km/h) |
| 95 mph (152.89 km/h) | 84.51 mph (136 km/h) |
| 100 mph (160.93 km/h) | 88.96 mph (143.16 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1441 | 1674 | 1803 | 1883 | 1969 | 2030 | 2098 | 2177 | 2288 | 2398 | 2521 | 2619 | 2797 | 2993 | 3146 | 3244 | 3300 | 3502 | 3784 | 4397 |
Better Fuel Economy Factory Ratios Increased Power
