Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 40/12.5-20 | 40/15.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 40.03 (1016.8) | 40.17 (1020.2) | 0.13 (3.4) 0.3% |
| Width inches (mm) | 12.52 (318) | 15.51 (394) | 2.99 (76) 23.9% |
| Circum. inches (mm) | 125.76 (3194.37) | 126.18 (3205.05) | 0.42 (10.68) 0.3% |
| Sidewall Height inches (mm) | 10.02 (254.4) | 10.08 (256.1) | 0.07 (1.7) 0.7% |
| Revolutions per mile (km) | 503.81 (313.05) | 502.13 (312.01) | -1.68 (-1.04) -0.3% |
40/15.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.07 mph (32.29 km/h) |
| 25 mph (40.23 km/h) | 25.08 mph (40.37 km/h) |
| 30 mph (48.28 km/h) | 30.1 mph (48.44 km/h) |
| 35 mph (56.33 km/h) | 35.12 mph (56.52 km/h) |
| 40 mph (64.37 km/h) | 40.13 mph (64.59 km/h) |
| 45 mph (72.42 km/h) | 45.15 mph (72.66 km/h) |
| 50 mph (80.47 km/h) | 50.17 mph (80.74 km/h) |
| 55 mph (88.51 km/h) | 55.18 mph (88.81 km/h) |
| 60 mph (96.56 km/h) | 60.2 mph (96.88 km/h) |
| 65 mph (104.61 km/h) | 65.22 mph (104.96 km/h) |
| 70 mph (112.65 km/h) | 70.23 mph (113.03 km/h) |
| 75 mph (120.7 km/h) | 75.25 mph (121.1 km/h) |
| 80 mph (128.75 km/h) | 80.27 mph (129.18 km/h) |
| 85 mph (136.79 km/h) | 85.28 mph (137.25 km/h) |
| 90 mph (144.84 km/h) | 90.3 mph (145.33 km/h) |
| 95 mph (152.89 km/h) | 95.32 mph (153.4 km/h) |
| 100 mph (160.93 km/h) | 100.33 mph (161.47 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1278 | 1484 | 1599 | 1669 | 1745 | 1800 | 1860 | 1930 | 2028 | 2126 | 2235 | 2322 | 2480 | 2654 | 2789 | 2876 | 2925 | 3105 | 3355 | 3899 |
Better Fuel Economy Factory Ratios Increased Power
