Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 40/12.5-20 | 305/70-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 40.03 (1016.8) | 36.81 (935) | -3.22 (-81.8) -8% |
| Width inches (mm) | 12.52 (318) | 12.01 (305) | -0.51 (-13) -4.1% |
| Circum. inches (mm) | 125.76 (3194.37) | 115.65 (2937.39) | -10.12 (-256.98) -8% |
| Sidewall Height inches (mm) | 10.02 (254.4) | 8.41 (213.5) | -1.61 (-40.9) -16.1% |
| Revolutions per mile (km) | 503.81 (313.05) | 547.88 (340.44) | 44.08 (27.39) 8.7% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.39 mph (29.6 km/h) |
| 25 mph (40.23 km/h) | 22.99 mph (37 km/h) |
| 30 mph (48.28 km/h) | 27.59 mph (44.4 km/h) |
| 35 mph (56.33 km/h) | 32.18 mph (51.8 km/h) |
| 40 mph (64.37 km/h) | 36.78 mph (59.2 km/h) |
| 45 mph (72.42 km/h) | 41.38 mph (66.59 km/h) |
| 50 mph (80.47 km/h) | 45.98 mph (73.99 km/h) |
| 55 mph (88.51 km/h) | 50.58 mph (81.39 km/h) |
| 60 mph (96.56 km/h) | 55.17 mph (88.79 km/h) |
| 65 mph (104.61 km/h) | 59.77 mph (96.19 km/h) |
| 70 mph (112.65 km/h) | 64.37 mph (103.59 km/h) |
| 75 mph (120.7 km/h) | 68.97 mph (110.99 km/h) |
| 80 mph (128.75 km/h) | 73.56 mph (118.39 km/h) |
| 85 mph (136.79 km/h) | 78.16 mph (125.79 km/h) |
| 90 mph (144.84 km/h) | 82.76 mph (133.19 km/h) |
| 95 mph (152.89 km/h) | 87.36 mph (140.59 km/h) |
| 100 mph (160.93 km/h) | 91.96 mph (147.99 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1394 | 1620 | 1744 | 1821 | 1904 | 1964 | 2029 | 2106 | 2213 | 2320 | 2438 | 2533 | 2705 | 2895 | 3044 | 3139 | 3192 | 3388 | 3661 | 4254 |
Better Fuel Economy Factory Ratios Increased Power
