Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/85-15 | 31/10.5-15 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.73 (780.5) | 30.98 (786.84) | 0.25 (6.34) 0.8% |
| Width inches (mm) | 9.25 (235) | 10.51 (267) | 1.26 (32) 13.6% |
| Circum. inches (mm) | 96.54 (2452.01) | 97.32 (2471.93) | 0.78 (19.92) 0.8% |
| Sidewall Height inches (mm) | 7.86 (199.75) | 7.99 (202.92) | 0.12 (3.17) 1.6% |
| Revolutions per mile (km) | 656.34 (407.83) | 651.05 (404.54) | -5.29 (-3.29) -0.8% |
31/10.5-15 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.16 mph (32.45 km/h) |
| 25 mph (40.23 km/h) | 25.2 mph (40.56 km/h) |
| 30 mph (48.28 km/h) | 30.24 mph (48.67 km/h) |
| 35 mph (56.33 km/h) | 35.28 mph (56.78 km/h) |
| 40 mph (64.37 km/h) | 40.32 mph (64.9 km/h) |
| 45 mph (72.42 km/h) | 45.37 mph (73.01 km/h) |
| 50 mph (80.47 km/h) | 50.41 mph (81.12 km/h) |
| 55 mph (88.51 km/h) | 55.45 mph (89.23 km/h) |
| 60 mph (96.56 km/h) | 60.49 mph (97.35 km/h) |
| 65 mph (104.61 km/h) | 65.53 mph (105.46 km/h) |
| 70 mph (112.65 km/h) | 70.57 mph (113.57 km/h) |
| 75 mph (120.7 km/h) | 75.61 mph (121.68 km/h) |
| 80 mph (128.75 km/h) | 80.65 mph (129.79 km/h) |
| 85 mph (136.79 km/h) | 85.69 mph (137.91 km/h) |
| 90 mph (144.84 km/h) | 90.73 mph (146.02 km/h) |
| 95 mph (152.89 km/h) | 95.77 mph (154.13 km/h) |
| 100 mph (160.93 km/h) | 100.81 mph (162.24 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1657 | 1925 | 2073 | 2164 | 2263 | 2334 | 2411 | 2503 | 2630 | 2757 | 2898 | 3010 | 3215 | 3440 | 3617 | 3730 | 3793 | 4026 | 4350 | 5055 |
Better Fuel Economy Factory Ratios Increased Power
