Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/80-15 | 37/13.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 35.47 (901) | 37.01 (940.18) | 1.54 (39.18) 4.3% |
| Width inches (mm) | 12.8 (325) | 13.5 (343) | 0.71 (18) 5.5% |
| Circum. inches (mm) | 111.44 (2830.57) | 116.29 (2953.66) | 4.85 (123.09) 4.3% |
| Sidewall Height inches (mm) | 10.24 (260) | 8.51 (216.09) | -1.73 (-43.91) -16.9% |
| Revolutions per mile (km) | 568.56 (353.28) | 544.86 (338.56) | -23.69 (-14.72) -4.2% |
37/13.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.87 mph (33.59 km/h) |
| 25 mph (40.23 km/h) | 26.09 mph (41.98 km/h) |
| 30 mph (48.28 km/h) | 31.3 mph (50.38 km/h) |
| 35 mph (56.33 km/h) | 36.52 mph (58.78 km/h) |
| 40 mph (64.37 km/h) | 41.74 mph (67.17 km/h) |
| 45 mph (72.42 km/h) | 46.96 mph (75.57 km/h) |
| 50 mph (80.47 km/h) | 52.17 mph (83.97 km/h) |
| 55 mph (88.51 km/h) | 57.39 mph (92.36 km/h) |
| 60 mph (96.56 km/h) | 62.61 mph (100.76 km/h) |
| 65 mph (104.61 km/h) | 67.83 mph (109.16 km/h) |
| 70 mph (112.65 km/h) | 73.04 mph (117.55 km/h) |
| 75 mph (120.7 km/h) | 78.26 mph (125.95 km/h) |
| 80 mph (128.75 km/h) | 83.48 mph (134.35 km/h) |
| 85 mph (136.79 km/h) | 88.7 mph (142.74 km/h) |
| 90 mph (144.84 km/h) | 93.91 mph (151.14 km/h) |
| 95 mph (152.89 km/h) | 99.13 mph (159.54 km/h) |
| 100 mph (160.93 km/h) | 104.35 mph (167.93 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1387 | 1611 | 1735 | 1811 | 1894 | 1953 | 2018 | 2095 | 2201 | 2307 | 2425 | 2519 | 2691 | 2879 | 3027 | 3121 | 3174 | 3369 | 3640 | 4231 |
Better Fuel Economy Factory Ratios Increased Power
