Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/55-18 | 32/12.5-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.34 (770.7) | 32.02 (813.36) | 1.68 (42.66) 5.5% |
| Width inches (mm) | 11.22 (285) | 12.52 (318) | 1.3 (33) 11.6% |
| Circum. inches (mm) | 95.32 (2421.23) | 100.6 (2555.25) | 5.28 (134.02) 5.5% |
| Sidewall Height inches (mm) | 6.17 (156.75) | 7.01 (178.08) | 0.84 (21.33) 13.6% |
| Revolutions per mile (km) | 664.68 (413.01) | 629.82 (391.35) | -34.86 (-21.66) -5.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.11 mph (33.97 km/h) |
| 25 mph (40.23 km/h) | 26.38 mph (42.46 km/h) |
| 30 mph (48.28 km/h) | 31.66 mph (50.95 km/h) |
| 35 mph (56.33 km/h) | 36.94 mph (59.44 km/h) |
| 40 mph (64.37 km/h) | 42.21 mph (67.94 km/h) |
| 45 mph (72.42 km/h) | 47.49 mph (76.43 km/h) |
| 50 mph (80.47 km/h) | 52.77 mph (84.92 km/h) |
| 55 mph (88.51 km/h) | 58.04 mph (93.41 km/h) |
| 60 mph (96.56 km/h) | 63.32 mph (101.91 km/h) |
| 65 mph (104.61 km/h) | 68.6 mph (110.4 km/h) |
| 70 mph (112.65 km/h) | 73.87 mph (118.89 km/h) |
| 75 mph (120.7 km/h) | 79.15 mph (127.38 km/h) |
| 80 mph (128.75 km/h) | 84.43 mph (135.87 km/h) |
| 85 mph (136.79 km/h) | 89.7 mph (144.37 km/h) |
| 90 mph (144.84 km/h) | 94.98 mph (152.86 km/h) |
| 95 mph (152.89 km/h) | 100.26 mph (161.35 km/h) |
| 100 mph (160.93 km/h) | 105.54 mph (169.84 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1603 | 1862 | 2005 | 2094 | 2189 | 2258 | 2333 | 2421 | 2544 | 2667 | 2803 | 2912 | 3110 | 3328 | 3499 | 3608 | 3669 | 3894 | 4208 | 4890 |
Better Fuel Economy Factory Ratios Increased Power
