Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 395/85-20 | 40/15.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 46.44 (1179.5) | 40.17 (1020.2) | -6.27 (-159.3) -13.5% |
| Width inches (mm) | 15.55 (395) | 15.51 (394) | -0.04 (-1) -0.3% |
| Circum. inches (mm) | 145.89 (3705.51) | 126.18 (3205.05) | -19.7 (-500.46) -13.5% |
| Sidewall Height inches (mm) | 13.22 (335.75) | 10.08 (256.1) | -3.14 (-79.65) -23.7% |
| Revolutions per mile (km) | 434.31 (269.87) | 502.13 (312.01) | 67.82 (42.14) 15.6% |
40/15.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.3 mph (27.84 km/h) |
| 25 mph (40.23 km/h) | 21.62 mph (34.8 km/h) |
| 30 mph (48.28 km/h) | 25.95 mph (41.76 km/h) |
| 35 mph (56.33 km/h) | 30.27 mph (48.72 km/h) |
| 40 mph (64.37 km/h) | 34.6 mph (55.68 km/h) |
| 45 mph (72.42 km/h) | 38.92 mph (62.64 km/h) |
| 50 mph (80.47 km/h) | 43.25 mph (69.6 km/h) |
| 55 mph (88.51 km/h) | 47.57 mph (76.56 km/h) |
| 60 mph (96.56 km/h) | 51.9 mph (83.52 km/h) |
| 65 mph (104.61 km/h) | 56.22 mph (90.48 km/h) |
| 70 mph (112.65 km/h) | 60.55 mph (97.44 km/h) |
| 75 mph (120.7 km/h) | 64.87 mph (104.4 km/h) |
| 80 mph (128.75 km/h) | 69.2 mph (111.36 km/h) |
| 85 mph (136.79 km/h) | 73.52 mph (118.32 km/h) |
| 90 mph (144.84 km/h) | 77.84 mph (125.28 km/h) |
| 95 mph (152.89 km/h) | 82.17 mph (132.24 km/h) |
| 100 mph (160.93 km/h) | 86.49 mph (139.2 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
