Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 120/85-18 | 185/85-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.03 (661.2) | 30.38 (771.7) | 4.35 (110.5) 16.7% |
| Width inches (mm) | 4.72 (120) | 7.28 (185) | 2.56 (65) 54.2% |
| Circum. inches (mm) | 81.78 (2077.22) | 95.45 (2424.37) | 13.67 (347.15) 16.7% |
| Sidewall Height inches (mm) | 4.02 (102) | 6.19 (157.25) | 2.18 (55.25) 54.2% |
| Revolutions per mile (km) | 774.76 (481.41) | 663.82 (412.48) | -110.94 (-68.93) -14.3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 23.34 mph (37.57 km/h) |
| 25 mph (40.23 km/h) | 29.18 mph (46.96 km/h) |
| 30 mph (48.28 km/h) | 35.01 mph (56.35 km/h) |
| 35 mph (56.33 km/h) | 40.85 mph (65.74 km/h) |
| 40 mph (64.37 km/h) | 46.68 mph (75.13 km/h) |
| 45 mph (72.42 km/h) | 52.52 mph (84.52 km/h) |
| 50 mph (80.47 km/h) | 58.36 mph (93.92 km/h) |
| 55 mph (88.51 km/h) | 64.19 mph (103.31 km/h) |
| 60 mph (96.56 km/h) | 70.03 mph (112.7 km/h) |
| 65 mph (104.61 km/h) | 75.86 mph (122.09 km/h) |
| 70 mph (112.65 km/h) | 81.7 mph (131.48 km/h) |
| 75 mph (120.7 km/h) | 87.53 mph (140.87 km/h) |
| 80 mph (128.75 km/h) | 93.37 mph (150.26 km/h) |
| 85 mph (136.79 km/h) | 99.21 mph (159.66 km/h) |
| 90 mph (144.84 km/h) | 105.04 mph (169.05 km/h) |
| 95 mph (152.89 km/h) | 110.88 mph (178.44 km/h) |
| 100 mph (160.93 km/h) | 116.71 mph (187.83 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1689 | 1962 | 2113 | 2207 | 2308 | 2379 | 2458 | 2552 | 2681 | 2811 | 2954 | 3069 | 3278 | 3508 | 3688 | 3803 | 3867 | 4105 | 4435 | 5154 |
Better Fuel Economy Factory Ratios Increased Power
