Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 175/90-18 | 170/85-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.4 (772.2) | 29.38 (746.2) | -1.02 (-26) -3.4% |
| Width inches (mm) | 6.89 (175) | 6.69 (170) | -0.2 (-5) -2.9% |
| Circum. inches (mm) | 95.51 (2425.94) | 92.29 (2344.26) | -3.22 (-81.68) -3.4% |
| Sidewall Height inches (mm) | 6.2 (157.5) | 5.69 (144.5) | -0.51 (-13) -8.3% |
| Revolutions per mile (km) | 663.39 (412.21) | 686.51 (426.57) | 23.11 (14.36) 3.5% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.33 mph (31.1 km/h) |
| 25 mph (40.23 km/h) | 24.16 mph (38.88 km/h) |
| 30 mph (48.28 km/h) | 28.99 mph (46.65 km/h) |
| 35 mph (56.33 km/h) | 33.82 mph (54.43 km/h) |
| 40 mph (64.37 km/h) | 38.65 mph (62.21 km/h) |
| 45 mph (72.42 km/h) | 43.48 mph (69.98 km/h) |
| 50 mph (80.47 km/h) | 48.32 mph (77.76 km/h) |
| 55 mph (88.51 km/h) | 53.15 mph (85.53 km/h) |
| 60 mph (96.56 km/h) | 57.98 mph (93.31 km/h) |
| 65 mph (104.61 km/h) | 62.81 mph (101.09 km/h) |
| 70 mph (112.65 km/h) | 67.64 mph (108.86 km/h) |
| 75 mph (120.7 km/h) | 72.47 mph (116.64 km/h) |
| 80 mph (128.75 km/h) | 77.31 mph (124.41 km/h) |
| 85 mph (136.79 km/h) | 82.14 mph (132.19 km/h) |
| 90 mph (144.84 km/h) | 86.97 mph (139.96 km/h) |
| 95 mph (152.89 km/h) | 91.8 mph (147.74 km/h) |
| 100 mph (160.93 km/h) | 96.63 mph (155.52 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1747 | 2030 | 2186 | 2282 | 2386 | 2461 | 2542 | 2639 | 2773 | 2907 | 3055 | 3174 | 3390 | 3628 | 3814 | 3933 | 4000 | 4245 | 4587 | 5330 |
Better Fuel Economy Factory Ratios Increased Power
